US3319102A - Electron gun assembly with increased cooling surfaces - Google Patents

Electron gun assembly with increased cooling surfaces Download PDF

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Publication number
US3319102A
US3319102A US408308A US40830864A US3319102A US 3319102 A US3319102 A US 3319102A US 408308 A US408308 A US 408308A US 40830864 A US40830864 A US 40830864A US 3319102 A US3319102 A US 3319102A
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US
United States
Prior art keywords
grid
cathode
base sleeve
electron gun
corrugated
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
Application number
US408308A
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English (en)
Inventor
Jay H Johnson
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.)
Kentucky Electronics Inc
Original Assignee
Kentucky Electronics Inc
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
Priority to NL296882D priority Critical patent/NL296882A/xx
Priority claimed from US217790A external-priority patent/US3204141A/en
Priority to GB28174/63A priority patent/GB1011441A/en
Priority to DE19631464759 priority patent/DE1464759A1/de
Application filed by Kentucky Electronics Inc filed Critical Kentucky Electronics Inc
Priority to US408308A priority patent/US3319102A/en
Priority to FR36847A priority patent/FR1452467A/fr
Application granted granted Critical
Publication of US3319102A publication Critical patent/US3319102A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/48—Electron guns
    • H01J29/485—Construction of the gun or of parts thereof
    • 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
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/48—Electron guns

Definitions

  • This invention relates to electronic discharge devices and methods of assembly, such as a cathode ray electron tube and more particularly to electron gun structures adapted for use therein, and is a division of my copending application S.N. 217,790 filed Aug. 20, 1962, now Patent No. 3,204,141, for Electron Gun.
  • Another object of the invention is to provide a control grid structure which will permit the accurate spacing of the surface of the grid and the surface of the cathode in an electron gun.
  • this novel electron gun assembly includes a cathode, first and second grids, and is suitable for a lowvoltage, low-current, transistor-operated television picture tube.
  • a low-voltage tube requires close-r spacing of the cathode and grid surfaces of the electron gun, and the closer spacing in turn greatly increases the importance of stability of the spacing. The problem of stability of spacing is not, however, confined to low-voltage tubes.
  • this novel gun incorporates features which enable operation of the gun with greatly reduced current drain.
  • One of these features is the method of mounting the cathode sleeve cylinder and base sleeve in the ceramic disc insulator whereby there is a minimal physical thermal contact between the metal cathode structure and the ceramic insulator disc structure and thereby less heat transfer or loss from the cathode to the disc.
  • Another feature is the smaller beam apertures in the grids which reduce the size of the beam and the power needed to form and accelerate it.
  • the smaller grid apertures also have the very signifisant incidental benefit of These dimensional tolerances are particuproviding a more well-defined picture through means of the sharper beam of electrons striking the face of the picture tube.
  • a thinner effective surface is needed on both grids in order to provide the closer spacing and smaller grid apertures necessary for a transistor operated, low-power television set. Also it is advantageous in provision of tools and dies which produce such par-ts to very close tolerances.
  • these surfaces are much thinner than those heretofore used.
  • the walls of the grid structure are about .010 inch thick in order to provide a stable support for the effective surface.
  • One existing method for providing a thinner effective surface is to coin the effective area immediately surrounding the grid aperture to a thinner wall thickness.
  • the grid of the subject gun may have Wall thickness of as low as 001:.00025 which will provide a uniform end wall of that thickness.
  • the tolerance on the material is reduced 50 percent which results in a more uniform wall thickness.
  • the uniform thinness of the end wall is advantageous for closer spacing between electrodes.
  • This grid may be fabricated from the thinner material with sufficient structural rigidity because of the corrugation around the conical surface.
  • Thermal stability of the grid structure is provided by the lancing around the end wall with four small equidistant lance webs which permits horizontal thermal expansion in the direction of least resistance and thereby prevents bowing of the end wall due to thermal expansion.
  • This lan-ced grid structure also permits heat fiow from the area which would otherwise be enclosed by the grid.
  • the lancing also permits accurate spacing between the end wall of the first grid and the coated surface of the cathode upon assembly by the insertion and withdrawal of a precision spacer gauge.
  • corrugated surface of the grid which provides a greater surface area and, therefore, a means of greater themal radiation. It also povides gaps where the frustoconical structure is secured to the cy lindrical portion of the first grid, allowing heat flow out of the area which would otherwise be enclosed by the first grid between the end wall of the first grid and the cathode ceramic disc. Further, the corrugated surface of the grid provides structural rigidity to resist movement of the end wall due to thermal expansion.
  • Still another feature is the temperature control of the cathode which is provided by the use of the base cathode sleeve as a heat sink with control of the cathode temperature by means of the length and thickness of the base sleeve, alloy material used in the base sleeve as stainless steel, coating of base sleeve as by carbonizing, or by addition of flanges, ribs, grooves, or dimples to the base sleeve; and the reduced heat loss, through conduction from the cathode to ceramic disc, resulting from the minimal thermal contact between ceramic disc and cathode.
  • FIG. 1 is a view in section of an electron gun including cathode, control grid, and screen grid embodying the invention
  • FIG. 2 is an enlarged view in section of a portion of the illustrative electron gun of FIGURE 1 as taken along lines lI-II of FIGURE 3;
  • FIG. 3 is a plan view looking into the control grid of an electron gun constructed in accordance with an embodiment of this invention.
  • FIG. 4 is a fragmental view in section of FIGURE 2 illustrative of the spacing methods afforded by this invention.
  • FIGURES l and 2 there is depicted one illustrative embodiment of this invention in which the cathode 4-0 is supported by a cathode base sleeve 42, which base sleeve contacts ceramic disc 44- in a very limited surface area contact to reduce the heat transfer from the cathode to the ceramic disc :4 which was norrnally experienced in prior art devices.
  • Tie ceramic disc is enclosed by a cylindrical member 46 and the disc 44 is held in position by means of an annular ring 48 which is oined to the cylinder 46 by any convenient means, such as by brazing.
  • the base sleeve 40 is fabricated from a non-emitting or low-emitting material such as stainless steel, or the outer surface of the base sleeve is coated with a non-emitting material to prevent the deposit of short-circuiting paths across the adjacent surface of the ceramic ring 44.
  • a first control grid 52 engages the outer surface of cylinder 46 and has a surface substantially parailel to the cathode emitting surface. This first grid is corrugated except for surface ltiZ as shown in FIGURE 3 and has one or more small apertures to permit the passage of electrons therethrough.
  • a second screen grid '54 is a combination cylindrical and frustoconical structure and is corrugated similar to the first grid with the conical portions of the two grids facing in opposite directions.
  • Grid 54 is supported from support rods 56 and '58 by means of supporting straps 60 and 62.
  • cylinder 48 is supported from the support rods by means of straps 64 and 66.
  • the corrugated frustoconical surfaces increase structural rigidity of both grid members, allowin the effective surfaces to be made with simpler dies to closer tolerances out of extremely thin and uniformly thin material permitting closer spacing and smaller apertures. On grid 52 it also increases heat radiation.
  • FIG. 2 which shows to an enlarged scale a portion of the gun assembly of FIG. I, is to be noted that the cathode at has an enlarged cylindrical portion 82 and a reduced cylindrical portion 84 connected thereto by means of an inturned flange portion 85 and the reduced portion 84 terminates in a flat electron emitting end wall 87.
  • the cathode base sleeve 42 is made of non-emitting or lowemitting material or has a non-emitting surface 43 on the enlarged cylindrical portion 38.
  • the other end of the base sleeve has an inturned shoulder 90, a reduced cylindrical portion 92 and an out-turned lip 94.
  • this gun assembly includes means for establishing testing the spacing between grid 52 and cathode 34 as illustrated in FIGURE 4 by the calibrated shim 8'9 inserted in the grid holes 108 to permit positioning cathode surface 87 an exact distance from grid surface 102.
  • Further means for testing the spacing after assembly includes holes such as 95 in the cathode base sleeve 42 above the shoulder of cathode 82.
  • the control grid 52 has fiat surface portion 102 substantially parallel to the cathode emitting surface '87 and this fiat cylindrical surface is raised or partially separated from a circular shoulder surface area 106 by means of a plurality of spaced lancing or lacing webs 108. These lacing webs permit the escape of heat the-rebetween such that the heat from the cathode 40 may escape without causing undue expansion of the first grid 52.
  • the frustoconical section 110 of the grid 52 has a corrugated surface which extends into the cylindrical section 112. The corrugated cylindrical portion 112 engages the supporting cylinder 46 only at spaced intervals, while providing a series of heat passages between these two members more adequately to ventilate the area around the cathode and thereby further reduce thermal expansion and movement of the members.
  • an electron gun assembly comprising an annular support ring, an annular ceramic ring supported by said supporting ring or the inner surface thereof, said ceramic ring having an inner flange of reduced thickness including a pair of substantially parallel sides, a cathode base sleeve within said ceramic ring and having an out-turned lip which engages one of the substantial'ly parallel sides of said inner flange, said cathode base sleeve having a shoulder which engages the other of said parallel sides whereby the conductive heat transfer between said cathode base sleeve and said ceramic ring takes place only at said out-turned lip and said shoulder of said base sleeve, and a first control grid having a cylindrical portion, a frustroconical portion connected to said cylindrical portion and a planar portion connected to said frustoconical portion, said planar portion having an aperture in the center thereof and being spaced from and substantially parallel to said emitting surface, wherein said cylindrical portion of said grid is corrugated, the inner surface of said corrug
  • planar portion includes a second section positioned in a plane substantially parallel to said first section and a plurality of webs spaced about said first section and connecting said first and second sections whereby heat escapes from said cathode between said Webs.
  • the combination further comprising a second grid mounted in spaced relationship to said first control grid, said second grid including a cylindrical portion, a frustoconical portion and a planar portion wherein the frustoconical portion slopes toward said first control grid.
  • control grid having both said cylindrical and said frustoconical portions corrugated.
  • control grid assembly defined in claim 6 further comprising air vent apertures through said cathode- ,ceramic disc assembly communicating with said air flow vents in said control grid to permit the passage of an air flow stream through said air vents as a measure of the cathode-grid spacing.

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  • Electrodes For Cathode-Ray Tubes (AREA)
US408308A 1962-08-20 1964-11-02 Electron gun assembly with increased cooling surfaces Expired - Lifetime US3319102A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL296882D NL296882A (de) 1962-08-20
GB28174/63A GB1011441A (en) 1962-08-20 1963-07-16 Electron gun
DE19631464759 DE1464759A1 (de) 1962-08-20 1963-08-19 Kathodenstrahlroehre
US408308A US3319102A (en) 1962-08-20 1964-11-02 Electron gun assembly with increased cooling surfaces
FR36847A FR1452467A (fr) 1962-08-20 1965-10-30 Canon à électrons et méthodes d'assemblage de celui-ci

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US217790A US3204141A (en) 1962-08-20 1962-08-20 Electron gun
US408308A US3319102A (en) 1962-08-20 1964-11-02 Electron gun assembly with increased cooling surfaces

Publications (1)

Publication Number Publication Date
US3319102A true US3319102A (en) 1967-05-09

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US408308A Expired - Lifetime US3319102A (en) 1962-08-20 1964-11-02 Electron gun assembly with increased cooling surfaces

Country Status (4)

Country Link
US (1) US3319102A (de)
DE (1) DE1464759A1 (de)
GB (1) GB1011441A (de)
NL (1) NL296882A (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3728574A (en) * 1971-10-19 1973-04-17 Gte Sylvania Inc Cathode cap
US3936686A (en) * 1973-05-07 1976-02-03 Moore Donald W Reflector lamp cooling and containing assemblies
US3983442A (en) * 1975-05-19 1976-09-28 Westinghouse Electric Corporation Electron gun cathode support structure
US4595858A (en) * 1984-12-03 1986-06-17 Rca Corporation Reinforcing means for a cup-shaped electron gun electrode
US5637952A (en) * 1993-04-26 1997-06-10 Nokia Technology Gmbh High-current cathode for picture tubes including a grid 3-electrode having a diaphragm with reduced apertures

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4313576C2 (de) * 1993-04-26 1996-07-18 Nokia Deutschland Gmbh Elektronenstrahlerzeugersystem
KR200190103Y1 (ko) * 1995-04-25 2000-08-01 김순택 음극선관용 전자총(electrol gun for cathode ray tube)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1595665A (en) * 1922-07-12 1926-08-10 Thomas W Kirkman Lightning arrester and method of making the same
US2443916A (en) * 1947-06-27 1948-06-22 Rca Corp Cathode-grid assembly for cathode-ray tubes
US2505095A (en) * 1946-05-09 1950-04-25 Rca Corp Diode for ultra high frequencies
US2582454A (en) * 1950-05-13 1952-01-15 Du Mont Allen B Lab Inc Cathode grid assembly
US2764708A (en) * 1953-03-20 1956-09-25 Int Standard Electric Corp Electron discharge devices
US2788460A (en) * 1951-05-23 1957-04-09 Itt Electrodes for electron discharge devices and methods of making same
US2963608A (en) * 1957-08-07 1960-12-06 Sylvania Electric Prod Cathode ray tube structure
US3027479A (en) * 1958-06-27 1962-03-27 Rca Corp Electron guns
US3204141A (en) * 1962-08-20 1965-08-31 Kentucky Electronics Inc Electron gun

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1595665A (en) * 1922-07-12 1926-08-10 Thomas W Kirkman Lightning arrester and method of making the same
US2505095A (en) * 1946-05-09 1950-04-25 Rca Corp Diode for ultra high frequencies
US2443916A (en) * 1947-06-27 1948-06-22 Rca Corp Cathode-grid assembly for cathode-ray tubes
US2582454A (en) * 1950-05-13 1952-01-15 Du Mont Allen B Lab Inc Cathode grid assembly
US2788460A (en) * 1951-05-23 1957-04-09 Itt Electrodes for electron discharge devices and methods of making same
US2764708A (en) * 1953-03-20 1956-09-25 Int Standard Electric Corp Electron discharge devices
US2963608A (en) * 1957-08-07 1960-12-06 Sylvania Electric Prod Cathode ray tube structure
US3027479A (en) * 1958-06-27 1962-03-27 Rca Corp Electron guns
US3204141A (en) * 1962-08-20 1965-08-31 Kentucky Electronics Inc Electron gun

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3728574A (en) * 1971-10-19 1973-04-17 Gte Sylvania Inc Cathode cap
US3936686A (en) * 1973-05-07 1976-02-03 Moore Donald W Reflector lamp cooling and containing assemblies
US3983442A (en) * 1975-05-19 1976-09-28 Westinghouse Electric Corporation Electron gun cathode support structure
US4595858A (en) * 1984-12-03 1986-06-17 Rca Corporation Reinforcing means for a cup-shaped electron gun electrode
US5637952A (en) * 1993-04-26 1997-06-10 Nokia Technology Gmbh High-current cathode for picture tubes including a grid 3-electrode having a diaphragm with reduced apertures

Also Published As

Publication number Publication date
NL296882A (de)
DE1464759A1 (de) 1968-11-07
GB1011441A (en) 1965-12-01

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