US3902093A - Cathode heater element with a dark heat radiating coating and method of producing such - Google Patents
Cathode heater element with a dark heat radiating coating and method of producing such Download PDFInfo
- Publication number
- US3902093A US3902093A US415256A US41525673A US3902093A US 3902093 A US3902093 A US 3902093A US 415256 A US415256 A US 415256A US 41525673 A US41525673 A US 41525673A US 3902093 A US3902093 A US 3902093A
- Authority
- US
- United States
- Prior art keywords
- heater element
- heat radiating
- aluminum oxide
- coating
- producing
- 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 - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/08—Manufacture of heaters for indirectly-heated cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
- H01J29/04—Cathodes
Definitions
- This object is attained by the use of a coating of insulating material applied to the filament which is completely porous and consists of a homogeneous dark colored sintered crystalline mixture of the insulating material, preferably aluminum oxide, A1 and of a refractory highmelting point metal such as tungsten.
- the present heater element has proven to be completely satisfactory and has durable insulating properties.
- An important advantage of this heater element is in the fact that it is particularly suitable for use in instant heat type cathodes.
- the heater element As regards the manufacture of the heater element, one method has proved to be particularly favorable. This is characterized by coating the filament with a layer of aluminum oxide and by simultaneously effecting electrolysis. The resulting porous insulating layer is then dried, the heater element is thereafter impregnated with an aqueous ammoniumtungstate solution, rinsed in a suitable liquid (such as methanol) and then dried again. Finally, the heater element is heated in a nitrogen and hydrogen atmosphere with the insulating layer being sintered.
- aqueous ammoniumtungstate solution such as methanol
- FIGURE schematically shows the construction of an indirectly heated cathode.
- a cathode tubing 3 has a cap 4 welded at one end which carries the emitting layer 5.
- the structure is secured by the holder 6 which is mounted to a supporting disc 7.
- the heater element consisting of the filament 2 coated with the insulating layer 1 is inserted into the tubing 3.
- the filament 2 is coated with a layer of insulating material 1 which is porous throughout, with no intermediate layers, and consists of a dark colored sintered crystalline mixture of the insulating material aluminum oxide, Al O and of a refractory highmelting point metal such as tungsten.
- the dark insulating layer 1 apart from the desired thermal properties, also provides very satisfactory results as regards insulating properties and long life, as well as only a very slight tendency toward melting during electrolysis.
- the layer is applied or deposited as follows.
- the heater element is dipped or immersed into a suitable coating bath containing a mixture of aluminum oxide, water, alcohol and salt, and the mixture is dissociated upon application of an electric voltage.
- the aluminum oxide which floats in the bath, is precipitated onto the cathode, i.e. on the filament. Simultaneously, during this electrophoretic process, hydrogen appears on the cathode due to the electrolysis.
- the mixture ratio it is possible to achieve a particular porosity for the precipitating oxide of aluminum which also has a particular elasticity.
- the coated filaments are removed from the coating bath, and dried.
- the dried heater elements are thereafter dipped into an aqueous ammonium-tungstate solution until the dried porous coat of insulating material is impregnated or saturated. In the course of a subsequent rising process, the heater element is again freed from a portion of the aqueous ammonium-tungstate solution.
- a suitable rinsing liquid may be methanol. This is followed by a further drying process.
- the heater element is heated in an oven having a nitrogen/hydrogen atmosphere up to a temperature of about 1500 to 2000C at which the insulating layer is sintered.
- a cathode heater element comprising a conductive filament having a coating of a dark colored heat radiating insulating material, said coating being porous throughout and including a non-emissive homogeneous dark colored sintered crystalline mixture of aluminum oxide and tungsten.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Solid Thermionic Cathode (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2317446A DE2317446C3 (de) | 1973-04-06 | 1973-04-06 | Verfahren zum Herstellen eines Heizelementes für eine indirekt geheizte Kathode |
Publications (1)
Publication Number | Publication Date |
---|---|
US3902093A true US3902093A (en) | 1975-08-26 |
Family
ID=5877284
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US415256A Expired - Lifetime US3902093A (en) | 1973-04-06 | 1973-11-12 | Cathode heater element with a dark heat radiating coating and method of producing such |
Country Status (10)
Country | Link |
---|---|
US (1) | US3902093A (fr) |
JP (1) | JPS5513102B2 (fr) |
BE (1) | BE813271R (fr) |
CA (1) | CA1032592A (fr) |
DE (1) | DE2317446C3 (fr) |
ES (1) | ES425053A1 (fr) |
FR (1) | FR2224866B1 (fr) |
GB (1) | GB1461495A (fr) |
IT (1) | IT1007777B (fr) |
NL (1) | NL7404521A (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4079164A (en) * | 1975-11-07 | 1978-03-14 | Hitachi, Ltd. | Base metal plate for directly heated oxide cathode |
US4208208A (en) * | 1977-11-18 | 1980-06-17 | Hitachi, Ltd. | Nickel alloy base metal plate for directly heated oxide cathodes |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4000435A (en) * | 1975-06-20 | 1976-12-28 | Westinghouse Electric Corporation | Electron gun cathode with a fast warm-up characteristic |
DE2835490C2 (de) * | 1978-08-12 | 1986-09-18 | Standard Elektrik Lorenz Ag, 7000 Stuttgart | Verfahren zur Herstellung einer indirekt geheizten Kathode |
DE2938248A1 (de) * | 1979-09-21 | 1981-03-26 | Standard Elektrik Lorenz AG, 70435 Stuttgart | Heizelement fuer eine indirekt geheizte kathode |
JPS573039U (fr) * | 1980-06-06 | 1982-01-08 | ||
DE3029853C2 (de) * | 1980-08-07 | 1982-08-26 | Standard Elektrik Lorenz Ag, 7000 Stuttgart | Indirekt durch Elektronenstoß geheizte Wehneltkathode |
DE19828158C1 (de) * | 1998-06-24 | 1999-11-25 | Siemens Ag | Indirekt geheizte Kathode, insbesondere für Röntgenröhren |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3029360A (en) * | 1958-04-29 | 1962-04-10 | Rca Corp | Heater wire coating process |
US3195004A (en) * | 1960-08-19 | 1965-07-13 | Rca Corp | Cathode heater for electron discharge devices |
US3372297A (en) * | 1964-09-28 | 1968-03-05 | Varian Associates | High frequency electron discharge devices and thermionic cathodes having improved (cvd) refractory insulation coated heater wires |
US3401297A (en) * | 1965-08-23 | 1968-09-10 | Varian Associates | Thermionic cathodes for electron discharge devices with improved refractory metal heater wires |
US3531678A (en) * | 1968-06-24 | 1970-09-29 | Raytheon Co | Heater with boron nitride coating |
US3558966A (en) * | 1967-03-01 | 1971-01-26 | Semicon Associates Inc | Directly heated dispenser cathode |
US3737714A (en) * | 1964-12-18 | 1973-06-05 | Sylvania Electric Prod | Dark coated heater for vacuum tube cathode |
US3765939A (en) * | 1972-05-10 | 1973-10-16 | Gte Sylvania Inc | Method of coating cathode heaters |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1017292B (de) * | 1956-07-18 | 1957-10-10 | Telefunken Gmbh | Aluminiumoxydueberzug fuer den Heizdraht mittelbar geheizter Kathoden elektrischer Entladungsroehren und Verfahren zur Herstellung eines Isolierueberzuges auf einem Heizdraht |
DE1146594B (de) * | 1961-10-31 | 1963-04-04 | Standard Elektrik Lorenz Ag | Aus zwei Schichten bestehender Isolationsueberzug fuer das Heizelement mittelbar geheizter Kathoden elektrischer Entladungsroehren und Verfahren zu seiner Herstellung |
DE1133835B (de) * | 1961-12-16 | 1962-07-26 | Telefunken Patent | Verfahren zur Herstellung einer mittelbar geheizten Kathode fuer eine elektrische Entladungsroehre |
BE626373A (fr) * | 1961-12-22 | |||
NL281567A (fr) * | 1962-07-30 | |||
DE1281038B (de) * | 1962-08-01 | 1968-10-24 | Telefunken Patent | Verfahren zur Herstellung einer mittelbar geheizten Kathode fuer eine elektrische Entladungsroehre |
US3246197A (en) * | 1962-10-02 | 1966-04-12 | Westinghouse Electric Corp | Cathode heater having an aluminum oxide and tungesten coating |
US3500454A (en) * | 1967-11-16 | 1970-03-10 | Sylvania Electric Prod | Insulator heater coating for heater-cathode assembly |
-
1973
- 1973-04-06 DE DE2317446A patent/DE2317446C3/de not_active Expired
- 1973-11-12 US US415256A patent/US3902093A/en not_active Expired - Lifetime
-
1974
- 1974-04-03 NL NL7404521A patent/NL7404521A/xx unknown
- 1974-04-04 BE BE2053530A patent/BE813271R/xx not_active IP Right Cessation
- 1974-04-05 GB GB1525974A patent/GB1461495A/en not_active Expired
- 1974-04-05 JP JP3809774A patent/JPS5513102B2/ja not_active Expired
- 1974-04-05 CA CA196,909A patent/CA1032592A/fr not_active Expired
- 1974-04-06 ES ES425053A patent/ES425053A1/es not_active Expired
- 1974-04-08 IT IT20992/74A patent/IT1007777B/it active
- 1974-04-08 FR FR7412243A patent/FR2224866B1/fr not_active Expired
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3029360A (en) * | 1958-04-29 | 1962-04-10 | Rca Corp | Heater wire coating process |
US3195004A (en) * | 1960-08-19 | 1965-07-13 | Rca Corp | Cathode heater for electron discharge devices |
US3372297A (en) * | 1964-09-28 | 1968-03-05 | Varian Associates | High frequency electron discharge devices and thermionic cathodes having improved (cvd) refractory insulation coated heater wires |
US3737714A (en) * | 1964-12-18 | 1973-06-05 | Sylvania Electric Prod | Dark coated heater for vacuum tube cathode |
US3401297A (en) * | 1965-08-23 | 1968-09-10 | Varian Associates | Thermionic cathodes for electron discharge devices with improved refractory metal heater wires |
US3558966A (en) * | 1967-03-01 | 1971-01-26 | Semicon Associates Inc | Directly heated dispenser cathode |
US3531678A (en) * | 1968-06-24 | 1970-09-29 | Raytheon Co | Heater with boron nitride coating |
US3765939A (en) * | 1972-05-10 | 1973-10-16 | Gte Sylvania Inc | Method of coating cathode heaters |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4079164A (en) * | 1975-11-07 | 1978-03-14 | Hitachi, Ltd. | Base metal plate for directly heated oxide cathode |
US4208208A (en) * | 1977-11-18 | 1980-06-17 | Hitachi, Ltd. | Nickel alloy base metal plate for directly heated oxide cathodes |
Also Published As
Publication number | Publication date |
---|---|
DE2317446B2 (de) | 1977-08-18 |
FR2224866B1 (fr) | 1978-11-03 |
CA1032592A (fr) | 1978-06-06 |
BE813271R (nl) | 1974-10-04 |
NL7404521A (fr) | 1974-10-08 |
FR2224866A1 (fr) | 1974-10-31 |
DE2317446C3 (de) | 1983-11-10 |
DE2317446A1 (de) | 1974-10-24 |
IT1007777B (it) | 1976-10-30 |
JPS5052962A (fr) | 1975-05-10 |
GB1461495A (en) | 1977-01-13 |
ES425053A1 (es) | 1976-11-16 |
JPS5513102B2 (fr) | 1980-04-07 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ALCATEL N.V., DE LAIRESSESTRAAT 153, 1075 HK AMSTE Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:INTERNATIONAL STANDARD ELECTRIC CORPORATION, A CORP OF DE;REEL/FRAME:004718/0023 Effective date: 19870311 |
|
AS | Assignment |
Owner name: NOKIA GRAETZ GESELLSCHAFT MIT BESCHRANKTER HAFTUNG Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ALCATEL N.V.;REEL/FRAME:007074/0030 Effective date: 19890130 |