US2894167A - Electron discharge device - Google Patents
Electron discharge device Download PDFInfo
- Publication number
- US2894167A US2894167A US345332A US34533253A US2894167A US 2894167 A US2894167 A US 2894167A US 345332 A US345332 A US 345332A US 34533253 A US34533253 A US 34533253A US 2894167 A US2894167 A US 2894167A
- Authority
- US
- United States
- Prior art keywords
- grid
- cathode
- control
- electron
- tube
- 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
- H01J21/00—Vacuum tubes
- H01J21/02—Tubes with a single discharge path
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J40/00—Photoelectric discharge tubes not involving the ionisation of a gas
- H01J40/16—Photoelectric discharge tubes not involving the ionisation of a gas having photo- emissive cathode, e.g. alkaline photoelectric cell
Definitions
- the present invention relates to an electron discharge device andmethod of'making same, and more particularly to such a device which utilizes cathode and control grid electrodes mounted in close proximity to each other.
- the electrodes comprising the tube such as the cathode, control grid, and anode, are arranged in suitable geometrical relation with respect to each other to enable the eifective control of electron flow from the cathode to the anode by means of the control grid which is interposed in a space between the cathode and anode.
- the cathode is electron emissive and may be constituted, for example, by photoelectric or thermally emissive materials, the electrons emitted by the cathode being collected by the anode after passing through the space partially occupied by the control grid.
- these electrons normally flow tothe anode in accordance with the controlling effect of the control grid.
- the biasing potential normally appliedto this grid is varied, in some circuits, to effect substantial current changes in the tube anode circuit.
- grid electrode By use of the grid electrode, it is possible to use small control voltages for controlling relatively large quantities of power in the anodecircuit, and the effectiveness of the gridin controlling this power, or the space current between the anode and cathode, may be represented by a mathematical expression characterized as grid plate transconductance (mutual conductance).
- grid plate transconductance mutant conductance
- an object of this invention to provide an electron discharge device having an electrode structure conducing to the highest possible value of gridplate transconductance.
- control gridelectrodes are so arranged with respect to each other that the control grid exercises a maximum of control over the-space discharge currentflowing betweenthe cathode and-the anode.
- the spacer elements are made to such negligible thickness as to provide almost contiguous mounting of the grid on the cathode surface to thereby position the grid where it will. be most effective.
- Fig. 1 isan axial section of an embodiment of the present invention.
- Fig. 2 is an enlarged fragmental section of a portion thereof.
- a highvacuum electron discharge device 1 is comprised of a glass or the like envelope 2 of conventional shape and construction and a transparent tubular reentrant supporting member 3 which may be made of glass or other suitable material as will appear hereinafter.
- An annular metal flange 4 made of some suitable material such as Kovar is affixed in the usual manner to the end 5 of the envelope 2 and another Kovar flange 6 is secured to a radially outwardly flaring lip 7 on the end of the support3.
- These flanges 4 and 6 are. suitably secured together such as by seam welding so as to provide a supporting connectionbetween the two members 2 and 3 and to position the member 3 centrally. of the envelope 2.
- the connections between the flanges 4 and 6 and the respective members 2 and 3 are such as to provide a hermetic seal for evacuating the space between the support 3 and the envelope 2.
- the electrode assembly of the tube which is generally cylindrical in the illustrated embodiment, is securely mounted on the outerperipheral surface of the support 3, and suitable wire leads 7a, 8 and 9, connect the electrodes of this assembly to terminal connections 10, 11 and 12, respectively, projecting through the glass envelope 2;
- the electron control electrode assembly shown in enlarged detail in Fig. 2, is comprised of a cathode, generally, indicated by the reference numeral 13, and a control grid element 14.
- the cathode itself is comprised of a first layer of metal 15 such as antimony or silver, which in the illustrated embodiment is thinenough to permitthe passage of light therethrough.
- This layer 15 is adhered to the outer peripheral surface of the support 3 by the use of any of the usual processes, such as by evaporation.
- the control grid 14- is comprised of a wire mesh screen of approximately 500 mesh size, and this screen is preformed to a tubular shape so as to fit over the cylindrical layer 15. Before assembling the grid 14 on the metallic layer 15, insulating spacers 16 are adhered tothe inner:
- the grid 14 is telescopedovertlie support and located axially thereof as shown in Fig. 1.
- the inner diameter of the grid14determined by the thickness of the spacers 16 is substantially coextensivewith the outer diameter of the metallic layer 15 to provide a snug, secure fit.
- the anode 17 is tubular in shape and is centered both axially and coaxially over the grid electrode 14 by glass or the like spacers 18. A plurality of tiny perforations 19 are provided in the wall of the anode 17 for a purpose which will be explained more fully hereafter.
- the terminal connection is conductively connected to the anode '17
- the cathode base is connected to the terminal 11
- the grid 14 is connected to'the terminal 12.
- the cathode base 15, the grid 14, and the anode 17 are assembled onto the support 3. It is important, however, that the grid 14 be cleaned of oxides (by means of hydrogen furnace or the like) before its assembly onto the tube. This assembly may be accomplished in the open atmosphere, the importance of which being explained more fully hereinafter.
- the support 3 with its electrode assembly is now located within the envelope 2 as shown in Fig. l, and the flanges 4 and 6 are seam- Welded to provide a vacuum tight container.
- the tube is next evacuated in the customary manner.
- cesium vapor is introduced into the tube by the use of the conventional techniques for depositing on the cathode base 15 (via the perforations 19), within the elemental areas 20 bordered by the various spacers or coating 16, a coating of cesium for making the cathode photosensitive. Irradiation of the elemental areas 20 will result in the emission of electrons which is directed radially outwardly through the grid openings.
- the surface of the grid 14 be such as will not permit the adherence thereto or chemical reaction therewith of the cesium vapor, and as a corollary, the conductive material of the cathode base 15 must be of such constituency (such as antimony oxide) as will combinewith the cesium vapor so as to provide the electron emissive areas Ztl as previously described.
- the cathode base 15 being comprised of either silver oxide or antimony oxide, and the grid 14 being composed of a material such as copper or nickel cleaned of its oxide surface, the cesium will adhere and react only with the cathode base.
- cathode base will be made electron emissive thereby providing the normal physical relationship between the cathode and control grid electrodes.
- the spacers or coatings 16 are of minimum thickness, that is, the spacers 16 are of such thickness as to position the grid 14 almost directly upon the surface of the cathode base 15 yet thick enough to provide electrical separation therebetween; It has been found that the control grid is most effective when the electric field of the grid is located immediately adjacent the emitting surface of the cathode, and from the description of the foregoing, it Will be seen that such field is positioned as close to the emitting surface of the cathode as appears to be possible.
- the electrode assembly is mounted on the support tube 3 in the open atmosphere.
- the proper treatment of the grid material as explained hereinbefore, makes this arrangement of assembly possible, the cesiation step in the method of fabrication serving to sensitize only the elemental areas 20 on the cathode base 15 and no other portion of the assembly.
- silver oxide usually constitutes the surface upon which the cesium is deposited, the silver oxide coating usually covering both the grid and cathode base materials.
- the cesium vapor is introduced into the evacuated envelope, both the grid and cathode surfaces are sensitized thereby reducing the operating efficiency of the finished tube.
- deposition of cesium takes place only on thebase material 15.
- the grid electrode has negligible but adequate spacing with re-. spect to the cathode 13, and that the grid is mounted rigidly with rmpect to the cathode. Such rigid mounting reduces the tendency of the grid to move relative;
- a lamp or similar light source is introduced in to. the reentrant support 3 to irradiate the photoelectric areas 20 from which electrons flow radially outwardly through the openings in the grid 14 to the anode 17;; While a photoelectric tube has been illustrated and de-;
- the base 15 may be composed of silver treated in any well known manner to make it thermally emissive.
- An electron flow-controlling assembly for an electron discharge device comprising an insulating support
- said elements being formed of metal selected from the group consisting of copper and nickel, insulating spacers separating said wire-like elements from said layer, said spacers contacting said layer at points directly beneath,v said wire-like elements, the elemental areas of said layer which are not contacted by said spacers only being electron emissive thereby providing intimately close but insulated spacing between such areas and said controlgrid element.
- the method of fabricating an electron discharge control assembly in the atmosphere comprising the steps of providing a base of conductive material on a supporting member, adhering an insulating material to one side of a control-grid element, mounting said control grid element on said supporting member with said insulating material directly contacting said conductive material, and activating the elemental areas of said conductive material which are not contacted by said insulation material to render said areas only electron-emissive.
- the method of fabricating an electron discharge control assembly in the atmosphere comprising the steps of providing a base of conductive material on a supporting member, adhering an insulating material to one side of a control-grid element, treating the control-grid element to remove oxide coating therefrom, mounting said control-grid element on said supporting member with said insulating material directly contacting said conductive material, and the elemental areas of said conductive material which are not contacted by said insulation material to render said areas only electron-emissive.
- the method of fabricating an electron discharge control assembly in the atmosphere comprising the steps of providing a base of conductive material on a supporting member, said conductive material being one of the group of antimony and silver, adhering an insulating material to one side of a control-grid element, said control grid element being composed of a material selected from the group of copper and nickel, treating the control-grid element to remove oxide coating therefrom, mounting said control-grid element on said conductive material whereby the insulating material separates the two, and subjecting the assembly to casium vapor, said cesium vapor adhering to said base but not to said element thereby rendering said base electron-emissive.
Description
United States Patent 'ELEC'DRON DISCHARGE DEVICE Cyril L. Day, Huntington, Ind., assignor to International Telephone and Telegraph Corporation, a corporation 0? d.
Application March130, 1953, SerialNo. 345,332
5 Claims. c1, 313-291 The present invention relates to an electron discharge device andmethod of'making same, and more particularly to such a device which utilizes cathode and control grid electrodes mounted in close proximity to each other. In conventional vacuum tube constructions, the electrodes comprising the tube, such as the cathode, control grid, and anode, are arranged in suitable geometrical relation with respect to each other to enable the eifective control of electron flow from the cathode to the anode by means of the control grid which is interposed in a space between the cathode and anode. The cathode is electron emissive and may be constituted, for example, by photoelectric or thermally emissive materials, the electrons emitted by the cathode being collected by the anode after passing through the space partially occupied by the control grid. In triode tubes, for example, these electrons normally flow tothe anode in accordance with the controlling effect of the control grid. The biasing potential normally appliedto this grid is varied, in some circuits, to effect substantial current changes in the tube anode circuit. By use of the grid electrode, it is possible to use small control voltages for controlling relatively large quantities of power in the anodecircuit, and the effectiveness of the gridin controlling this power, or the space current between the anode and cathode, may be represented by a mathematical expression characterized as grid plate transconductance (mutual conductance). In certain applications of vacuum tubes, it has been found highly desirable to have the highest possible value of grid-plate transconductanceandit has been found that the position of the control grid with respect to the cathode plays an important part in obtaining the desired value of such transconductance.
In view of the foregoing, it is an object of this invention to provide an electron discharge device having an electrode structure conducing to the highest possible value of gridplate transconductance.
It is another object of this invention to provide a vacuum tube cqnstructionin which the cathode and control,
gridelectrodes are so arranged with respect to each other that the control grid exercises a maximum of control over the-space discharge currentflowing betweenthe cathode and-the anode.
Itis still anotherobject ofthis invention to provide a vacuum tube construction having cathode and control grid electrodes which are uniquelyarranged so as to bring the two electrodes into extremely close proximity with each other while maintaining direct current electrical separation therebetween.
It is still anotherobject of this invention to provide, ina vacuum tube construction having control grid and cathode electrodes, a physical relationship between the two, electrodes which positions the control grid in the electron field adjacent thecathode where most effective control of the flow of these electrons may be obtained.
It is another object of this invention to provide a method for producing a photosensitive cathode in close proximity to a control grid whereby an insulating space between the cathode and control grid having an appreciably high resistance to leakage currents may be obtained.
In accordance with the present invention, there is provided a vacuum tube construction-comprised of a supporting member made of insulating material, a cathode surface provided on said supporting member, spaced conductive elements constituting a control grid provided on said cathode surface, and insulating spacer coating or elements adhered to the conductive elementsforseparating the grid from the cathode'surface. The spacer elements are made to such negligible thickness as to provide almost contiguous mounting of the grid on the cathode surface to thereby position the grid where it will. be most effective.
For a better understanding of the invention, together with other and further objects thereof, reference is made to the following descriptiontaken in connection with the accompanying drawings and its scope will be pointed out in the appendedclaims.
In the accompanying drawings:
Fig. 1 isan axial section of an embodiment of the present invention; and
Fig. 2 is an enlarged fragmental section of a portion thereof.
Referring to the drawings, a highvacuum electron discharge device 1 is comprised of a glass or the like envelope 2 of conventional shape and construction and a transparent tubular reentrant supporting member 3 which may be made of glass or other suitable material as will appear hereinafter. An annular metal flange 4 made of some suitable material such as Kovar is affixed in the usual manner to the end 5 of the envelope 2 and another Kovar flange 6 is secured to a radially outwardly flaring lip 7 on the end of the support3. These flanges 4 and 6 are. suitably secured together such as by seam welding so as to provide a supporting connectionbetween the two members 2 and 3 and to position the member 3 centrally. of the envelope 2. The connections between the flanges 4 and 6 and the respective members 2 and 3 are such as to provide a hermetic seal for evacuating the space between the support 3 and the envelope 2.
The electrode assembly of the tube, which is generally cylindrical in the illustrated embodiment, is securely mounted on the outerperipheral surface of the support 3, and suitable wire leads 7a, 8 and 9, connect the electrodes of this assembly to terminal connections 10, 11 and 12, respectively, projecting through the glass envelope 2;
The electron control electrode assembly, shown in enlarged detail in Fig. 2, is comprised of a cathode, generally, indicated by the reference numeral 13, and a control grid element 14. The cathode itself is comprised of a first layer of metal 15 such as antimony or silver, which in the illustrated embodiment is thinenough to permitthe passage of light therethrough. This layer 15 is adhered to the outer peripheral surface of the support 3 by the use of any of the usual processes, such as by evaporation. The control grid 14- is comprised of a wire mesh screen of approximately 500 mesh size, and this screen is preformed to a tubular shape so as to fit over the cylindrical layer 15. Before assembling the grid 14 on the metallic layer 15, insulating spacers 16 are adhered tothe inner:
to' provide the necessary electrical insulation between the cathode base 15 and the grid 14. In the preferred arrangement, it is desired to locate securely the grid 14 as close to the surface of the cathode base 15 as possible. Withthe spacers 16 properly secured to "the inner periphery to the grid 14, "the grid is telescopedovertlie support and located axially thereof as shown in Fig. 1. Preferably, the inner diameter of the grid14determined by the thickness of the spacers 16, is substantially coextensivewith the outer diameter of the metallic layer 15 to provide a snug, secure fit.
The anode 17 is tubular in shape and is centered both axially and coaxially over the grid electrode 14 by glass or the like spacers 18. A plurality of tiny perforations 19 are provided in the wall of the anode 17 for a purpose which will be explained more fully hereafter. As will be seen in Fig. 1, the terminal connection is conductively connected to the anode '17, the cathode base is connected to the terminal 11, and the grid 14 is connected to'the terminal 12.
In the assembly of the construction thus far described, the cathode base 15, the grid 14, and the anode 17 are assembled onto the support 3. It is important, however, that the grid 14 be cleaned of oxides (by means of hydrogen furnace or the like) before its assembly onto the tube. This assembly may be accomplished in the open atmosphere, the importance of which being explained more fully hereinafter. The support 3 with its electrode assembly is now located within the envelope 2 as shown in Fig. l, and the flanges 4 and 6 are seam- Welded to provide a vacuum tight container. The tube is next evacuated in the customary manner.
As a final step in the method of fabricating this tube, cesium vapor is introduced into the tube by the use of the conventional techniques for depositing on the cathode base 15 (via the perforations 19), within the elemental areas 20 bordered by the various spacers or coating 16, a coating of cesium for making the cathode photosensitive. Irradiation of the elemental areas 20 will result in the emission of electrons which is directed radially outwardly through the grid openings.
In fabrication, it is important that the surface of the grid 14 be such as will not permit the adherence thereto or chemical reaction therewith of the cesium vapor, and as a corollary, the conductive material of the cathode base 15 must be of such constituency (such as antimony oxide) as will combinewith the cesium vapor so as to provide the electron emissive areas Ztl as previously described. With the cathode base 15 being comprised of either silver oxide or antimony oxide, and the grid 14 being composed of a material such as copper or nickel cleaned of its oxide surface, the cesium will adhere and react only with the cathode base.
This precleaning of the grid is important because in the photoelectric tube, if the cesium adheringly deposits onto the grid 14, the grid becomes electron emissive which would defeat the normal function of the vacuum tube. cathode base will be made electron emissive thereby providing the normal physical relationship between the cathode and control grid electrodes.
As mentioned earlier,-the spacers or coatings 16 are of minimum thickness, that is, the spacers 16 are of such thickness as to position the grid 14 almost directly upon the surface of the cathode base 15 yet thick enough to provide electrical separation therebetween; It has been found that the control grid is most effective when the electric field of the grid is located immediately adjacent the emitting surface of the cathode, and from the description of the foregoing, it Will be seen that such field is positioned as close to the emitting surface of the cathode as appears to be possible.
In operation, electrons are emitted from the cathode surface, and those which possess sufiicient velocity to pass beyond the negatively charged grid are accelerated By following the preceding procedure, only the- 2,894,167 7, p r .1 1 m toward the anode. Most effective control of this flow of electrons is achieved by positioning the control grid as closely to the cathode surface as possible.
As mentioned earlier, the electrode assembly is mounted on the support tube 3 in the open atmosphere. The proper treatment of the grid material, as explained hereinbefore, makes this arrangement of assembly possible, the cesiation step in the method of fabrication serving to sensitize only the elemental areas 20 on the cathode base 15 and no other portion of the assembly.
In other prior art tube arrangements, silver oxide usually constitutes the surface upon which the cesium is deposited, the silver oxide coating usually covering both the grid and cathode base materials. Thus, when the cesium vapor is introduced into the evacuated envelope, both the grid and cathode surfaces are sensitized thereby reducing the operating efficiency of the finished tube. With the present arrangement, deposition of cesium takes place only on thebase material 15.
From the foregoing it will be apparent that the grid electrode has negligible but adequate spacing with re-. spect to the cathode 13, and that the grid is mounted rigidly with rmpect to the cathode. Such rigid mounting reduces the tendency of the grid to move relative;
to the cathode and to thereby develop microphonicsf Also, it is obvious that the present tube will withstand severe jarring and vibration which causes conventionaltubes to be noisy.
In the operation of the foregoing described embodiment, a lamp or similar light source is introduced in to. the reentrant support 3 to irradiate the photoelectric areas 20 from which electrons flow radially outwardly through the openings in the grid 14 to the anode 17;; While a photoelectric tube has been illustrated and de-;
scribed, it will appear obvious to those skilled in the art that the base 15 may be composed of silver treated in any well known manner to make it thermally emissive.-
While there has been described what is at presentconsidered the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims, to cover all such changes andv modifications as fall within the true spirit and scope of),
the invention.
What is claimed is:
1. An electron flow-controlling assembly for an electron discharge device comprising an insulating support,
and comprising a screen-like member having apertures, insulation adhered to one side only of said screen-like member, said insulation contacting said layer and con-' stituting a support and spacer for said screen-like memher, and electron-emissive material provided only on.
the elemental areas of said layer which are not contacted by said insulation thereby providing intimately close butinsulated spacing between such areas and said controlgrid element.
2. An electron-flow-controlling assembly for an elecductively connected spaced metallic wire-like elements,
said elements being formed of metal selected from the group consisting of copper and nickel, insulating spacers separating said wire-like elements from said layer, said spacers contacting said layer at points directly beneath,v said wire-like elements, the elemental areas of said layer which are not contacted by said spacers only being electron emissive thereby providing intimately close but insulated spacing between such areas and said controlgrid element.
3. The method of fabricating an electron discharge control assembly in the atmosphere comprising the steps of providing a base of conductive material on a supporting member, adhering an insulating material to one side of a control-grid element, mounting said control grid element on said supporting member with said insulating material directly contacting said conductive material, and activating the elemental areas of said conductive material which are not contacted by said insulation material to render said areas only electron-emissive.
4. The method of fabricating an electron discharge control assembly in the atmosphere comprising the steps of providing a base of conductive material on a supporting member, adhering an insulating material to one side of a control-grid element, treating the control-grid element to remove oxide coating therefrom, mounting said control-grid element on said supporting member with said insulating material directly contacting said conductive material, and the elemental areas of said conductive material which are not contacted by said insulation material to render said areas only electron-emissive.
5. The method of fabricating an electron discharge control assembly in the atmosphere comprising the steps of providing a base of conductive material on a supporting member, said conductive material being one of the group of antimony and silver, adhering an insulating material to one side of a control-grid element, said control grid element being composed of a material selected from the group of copper and nickel, treating the control-grid element to remove oxide coating therefrom, mounting said control-grid element on said conductive material whereby the insulating material separates the two, and subjecting the assembly to casium vapor, said cesium vapor adhering to said base but not to said element thereby rendering said base electron-emissive.
References Cited in the file of this patent UNITED STATES PATENTS 1,839,899 Slepian Jan. 5, 1932 1,861,637 Marden et a1. June 7, 1932 1,942,501 Stillwell Jan. 9, 1934 1,965,849 McIlvaine July 10, 1934 2,120,916 Bitner June 14, 1938 2,290,748 Hergenrother July 21, 1942 2,601,024 Jacobs et a1 June 17, 1952 FOREIGN PATENTS 115,700 Great Britain May 21, 1918
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US345332A US2894167A (en) | 1953-03-30 | 1953-03-30 | Electron discharge device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US345332A US2894167A (en) | 1953-03-30 | 1953-03-30 | Electron discharge device |
Publications (1)
Publication Number | Publication Date |
---|---|
US2894167A true US2894167A (en) | 1959-07-07 |
Family
ID=23354614
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US345332A Expired - Lifetime US2894167A (en) | 1953-03-30 | 1953-03-30 | Electron discharge device |
Country Status (1)
Country | Link |
---|---|
US (1) | US2894167A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3066236A (en) * | 1958-05-14 | 1962-11-27 | Int Standard Electric Corp | Electron discharge devices |
US3121648A (en) * | 1960-04-29 | 1964-02-18 | Westinghouse Electric Corp | Radiant energy converter |
US3317771A (en) * | 1963-10-31 | 1967-05-02 | Varian Associates | Photo-emissive electron device |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB115700A (en) * | ||||
US1839899A (en) * | 1923-10-15 | 1932-01-05 | Westinghouse Electric & Mfg Co | Space current device |
US1861637A (en) * | 1927-10-27 | 1932-06-07 | Westinghouse Lamp Co | Production of alkali metal tubes |
US1942501A (en) * | 1927-04-06 | 1934-01-09 | Bell Telephone Labor Inc | Light-sensitive tube |
US1965849A (en) * | 1927-07-29 | 1934-07-10 | Mcllvaine Patent Corp | Electronic tube |
US2120916A (en) * | 1934-09-22 | 1938-06-14 | Ralph E Bitner | Light frequency converter |
US2290748A (en) * | 1941-03-05 | 1942-07-21 | Hazeltine Corp | Vacuum tube and method of manufacture thereof |
US2601024A (en) * | 1949-07-26 | 1952-06-17 | Sylvania Electric Prod | Electrode structure for electron discharge devices |
-
1953
- 1953-03-30 US US345332A patent/US2894167A/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB115700A (en) * | ||||
US1839899A (en) * | 1923-10-15 | 1932-01-05 | Westinghouse Electric & Mfg Co | Space current device |
US1942501A (en) * | 1927-04-06 | 1934-01-09 | Bell Telephone Labor Inc | Light-sensitive tube |
US1965849A (en) * | 1927-07-29 | 1934-07-10 | Mcllvaine Patent Corp | Electronic tube |
US1861637A (en) * | 1927-10-27 | 1932-06-07 | Westinghouse Lamp Co | Production of alkali metal tubes |
US2120916A (en) * | 1934-09-22 | 1938-06-14 | Ralph E Bitner | Light frequency converter |
US2290748A (en) * | 1941-03-05 | 1942-07-21 | Hazeltine Corp | Vacuum tube and method of manufacture thereof |
US2601024A (en) * | 1949-07-26 | 1952-06-17 | Sylvania Electric Prod | Electrode structure for electron discharge devices |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3066236A (en) * | 1958-05-14 | 1962-11-27 | Int Standard Electric Corp | Electron discharge devices |
US3121648A (en) * | 1960-04-29 | 1964-02-18 | Westinghouse Electric Corp | Radiant energy converter |
US3317771A (en) * | 1963-10-31 | 1967-05-02 | Varian Associates | Photo-emissive electron device |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2275864A (en) | Cathode ray tube | |
US2883576A (en) | Thermionic valves | |
US2722624A (en) | Electron tube | |
US2914694A (en) | Cathode assembly | |
US2894167A (en) | Electron discharge device | |
US2708250A (en) | Tube assembly | |
US2967260A (en) | Electron tube | |
US4721882A (en) | Cathode ray tube | |
US3067348A (en) | Pickup tube target structure | |
US2455868A (en) | Control grid for electric discharge devices and method of making same | |
US4445873A (en) | Method of producing magnetrons | |
US3183388A (en) | Electron gun particle barrier formed by plurality of flexible radial sectors | |
US4370585A (en) | Evaporator support assembly for a photomultiplier tube | |
US2178747A (en) | Shielded metal discharge tube | |
US2870364A (en) | Electron discharge device | |
US2802133A (en) | Electron discharge device | |
US2592242A (en) | Electron gun and mounting therefor | |
US2190695A (en) | Secondary electron emitter and method of making it | |
US2082638A (en) | Electrical discharge device | |
US3183391A (en) | Shielding of electron gun from vaporized getter by decomposable foil over electrode aperture | |
US2219107A (en) | Electron discharge device | |
US2825832A (en) | Thermionic cathode structure | |
US5418425A (en) | Multistage collector for electron-beam tubes having collector electrodes indirectly connected by collar members | |
US4554481A (en) | Electron discharge device having a ceramic member with means for reducing luminescence therein | |
US2227030A (en) | Electron amplifier |