US3584252A - Electrically-shielded symbol-display tube - Google Patents

Electrically-shielded symbol-display tube Download PDF

Info

Publication number
US3584252A
US3584252A US827337A US3584252DA US3584252A US 3584252 A US3584252 A US 3584252A US 827337 A US827337 A US 827337A US 3584252D A US3584252D A US 3584252DA US 3584252 A US3584252 A US 3584252A
Authority
US
United States
Prior art keywords
envelope
tube
display tube
electrically
electrically conductive
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
US827337A
Inventor
Richard Du Bois Jr
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.)
Cooper Industries LLC
Original Assignee
Wagner Electric Corp
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 Wagner Electric Corp filed Critical Wagner Electric Corp
Application granted granted Critical
Publication of US3584252A publication Critical patent/US3584252A/en
Assigned to STUDEBAKER-WORTHINGTON, INC. reassignment STUDEBAKER-WORTHINGTON, INC. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WAGNER ELECTRIC CORPORATION
Assigned to EDISON INTERNATONAL, INC. reassignment EDISON INTERNATONAL, INC. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: STUDEBAKER-WORTHINGTON, INC., A CORP. OF DE
Assigned to COOPER INDUSTRIES, INC., 1001 FANNIN, HOUSTON, TEXAS 77002, A CORP. OF reassignment COOPER INDUSTRIES, INC., 1001 FANNIN, HOUSTON, TEXAS 77002, A CORP. OF ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: EDISON INTERNATIONAL, INC., A CORP. OF DE.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00Cathode ray tubes; Electron beam tubes
    • H01J31/08Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • H01J31/15Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen with ray or beam selectively directed to luminescent anode segments

Definitions

  • the present invention relates to an improved symbol-display tube.
  • a tube may employ a number' of phosphorescent, selectively energizable anodes mounted in an evacuated glass envelope with one or more thermionic cathodes to provide an electron beam or beams with which the anodes are selectively bombarded.
  • Certain of these symboldisplay tubes operate with relatively low voltages, and thus are vulnerable to the effects to electrical fields imposed upon them in the environment in which they are employed.
  • Such a low-voltage tube is disclosed in copending application Ser. No. 7Sl,l68, filed by Rein Raago on Aug. 8, 1968.
  • the present invention specifically comprises an electrically conductive shielding layer disposed about a portion of the envelope of the tube. When grounded, this shielding layer serves as a shield against the aforementioned electrical fields. When placed at a negative potential with respect to the cathode, the shielding layer serves to blank out the display by preventing electrons from reaching the anodes. Since the anodes-tocathode circuit carries current and the shielding layer does not carry current, it is advantageous to perform the blanking function by placing the shielding layer at the proper potential than by opening the anodes-to-cathode circuit.
  • FIG. 1 is a sectional view of one embodiment of the symboldisplay tube taken through line l-l, shown connected to external power and switching circuitry.
  • FIG. 2 is a sectional view of one embodiment of the symboldisplay tube taken through line 2-2; the several electrical connectors associated with the anode elements and with the cathode have been omitted for the sake of clarity.
  • the display tube 10 comprises an envelope 12, preferably of glass, with cathodes 14A and 14B mounted therein between the viewing surface of envelope 12 and anode elements 16A, 16B, 16C, 16D, 16E, 16F, and 166.
  • the anode elements are arranged to form a FIG. 8.
  • the glass envelope 12 has a thickened base portion through which pass electrical connectors 20A, 20B, 20C, 20D, 20E, 20F and 200, which support the anode elements 16A, 16B, 16C, 16D, 16E, 16F and 166, respectively.
  • the electrically conductive shielding layer 26 is preferably disposed about a section of the inner surface of the cylindrical portion of the envelope 12.
  • the shielding layer 26 may also be disposed about a corresponding section of the outer surface of envelope 12.
  • the shielding layer 26 is electrically connnected to exterior circuitry by means of conductive spring contacts 28 which are connected to lead wire 30.
  • the shielding layer 26 may be connected to the cathodes within the envelope without any provision for connection to external circuitry. In such an embodiment, the layer 26 will perform its shielding function, but will not be utilizable for blanking out the display.
  • the external circuitry for controlling the symbol-display tube comprises a switching system 32 to selectively connecting the anode elements to a source of electrical power 34.
  • a switch 36 serves to connect the shielding layer 26 to ground to enable it to perform the shielding function, and enables the shielding layer to be placed at a negative potential with respect to the cathodes by connecting it to the negative terminal of a source of electromotive force 38.
  • a heating current source 40 is connected between electrical connectors 22 and 24 to render the cathodes 14A and 14B thermoemissive.
  • a symbol display tube including a sealed envelope having a substantially cylindrical portion, a plurality of display elements and means for bombarding said display elements with electrons when said tube is connected to a source of external power and switching circuitry, the improvement comprising: an electrically conductive layer disposed on about at least half of the circumference of said cylindrical portion of the envelope to form an electrical shield for the display elements within the envelope, and connecting means for connecting said layer to the external circuitry 2.
  • said connecting means comprises:
  • a conductive spring disposed substantially diametrically within the envelope to contact the electrically conductive layer at two points;

Landscapes

  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)

Abstract

An electrically conductive layer coextensive with at least a portion of the envelope of a symbol-display tube is operative to shield the tube from external electric fields.

Description

United States Patent Richard Du Bois, J r. Caldwell Township, NJ. Appl. No. 827,337
Filed May 23, 1969 Patented June 8, 1971.
Assignee Wagner Electric Corporation Inventor ELECTRlCALLY-SHIELDED SYMBOL DISPLAY TUBE 2 Claims, 2 Drawing Figs.
US. Cl 313/l09.5, 313/313 Int. Cl 1101j 1/52 Field of Search 313/109.5, 291, 313, 210
m 204 m 200 w r or [56] References Cited UNITED STATES PATENTS 1,583,414 5/1926 (Jill etal 2,307,027 1/1943 Davie et al.........
Gowell 2,420,311 5/1947 3,062,980 1 1/1962 Bawdekar 3,508,101 4/1970 Tanji 2,343,630 3/1944 Atwood,Jr.
FOREIGN PATENTS 234,906 6/1925 Great Britain Primary Examiner-Roy Lake Assistant Examiner- Palmer C. Demeo Attorney-Eyre, Mann and Lucas 313/313 313/313 3l3/3l3X 313/313X 3l3/l09.5 313/313X ABSTRACT: An electrically conductive layer coextensive with at least a portion of the envelope of a symbol-display tube is operative to shield the tube from external electric fields.
ELECTRlCALLY-SHIELDED SYMBOL DISPLAY TUBE The present invention relates to an improved symbol-display tube. Such a tube may employ a number' of phosphorescent, selectively energizable anodes mounted in an evacuated glass envelope with one or more thermionic cathodes to provide an electron beam or beams with which the anodes are selectively bombarded. Certain of these symboldisplay tubes operate with relatively low voltages, and thus are vulnerable to the effects to electrical fields imposed upon them in the environment in which they are employed. Such a low-voltage tube is disclosed in copending application Ser. No. 7Sl,l68, filed by Rein Raago on Aug. 8, 1968. The present invention specifically comprises an electrically conductive shielding layer disposed about a portion of the envelope of the tube. When grounded, this shielding layer serves as a shield against the aforementioned electrical fields. When placed at a negative potential with respect to the cathode, the shielding layer serves to blank out the display by preventing electrons from reaching the anodes. Since the anodes-tocathode circuit carries current and the shielding layer does not carry current, it is advantageous to perform the blanking function by placing the shielding layer at the proper potential than by opening the anodes-to-cathode circuit. A better understanding of the present invention may be had by referring to the accompanying drawings, of which:
FIG. 1 is a sectional view of one embodiment of the symboldisplay tube taken through line l-l, shown connected to external power and switching circuitry.
FIG. 2 is a sectional view of one embodiment of the symboldisplay tube taken through line 2-2; the several electrical connectors associated with the anode elements and with the cathode have been omitted for the sake of clarity.
Referring specifically to FIG. 1, the display tube 10 comprises an envelope 12, preferably of glass, with cathodes 14A and 14B mounted therein between the viewing surface of envelope 12 and anode elements 16A, 16B, 16C, 16D, 16E, 16F, and 166. In this embodiment, the anode elements are arranged to form a FIG. 8. The glass envelope 12 has a thickened base portion through which pass electrical connectors 20A, 20B, 20C, 20D, 20E, 20F and 200, which support the anode elements 16A, 16B, 16C, 16D, 16E, 16F and 166, respectively. Electrical connectors 22 and 24 are attached to the terminals of the cathodes 14A and 14B and extend through the thickened base portion 18 for connection to a source of power. The electrically conductive shielding layer 26 is preferably disposed about a section of the inner surface of the cylindrical portion of the envelope 12. The shielding layer 26 may also be disposed about a corresponding section of the outer surface of envelope 12. In the preferred embodiment shown in FIGS. 1 and 2, the shielding layer 26 is electrically connnected to exterior circuitry by means of conductive spring contacts 28 which are connected to lead wire 30. However, the shielding layer 26 may be connected to the cathodes within the envelope without any provision for connection to external circuitry. In such an embodiment, the layer 26 will perform its shielding function, but will not be utilizable for blanking out the display.
The external circuitry for controlling the symbol-display tube comprises a switching system 32 to selectively connecting the anode elements to a source of electrical power 34. A switch 36 serves to connect the shielding layer 26 to ground to enable it to perform the shielding function, and enables the shielding layer to be placed at a negative potential with respect to the cathodes by connecting it to the negative terminal of a source of electromotive force 38. A heating current source 40 is connected between electrical connectors 22 and 24 to render the cathodes 14A and 14B thermoemissive.
The advantages of the present invention, as well as certain changes and modifications to the disclosed embodiment thereof, will be readily apparent to those skilled in the art. It is the a plicant's intention to cover all those changes and modl lcations which could be made to the embodlment of the invention herein chosen for the purposes of the disclosure without departing from the spirit and scope of the invention.
What I claim is:
1. In a symbol display tube including a sealed envelope having a substantially cylindrical portion, a plurality of display elements and means for bombarding said display elements with electrons when said tube is connected to a source of external power and switching circuitry, the improvement comprising: an electrically conductive layer disposed on about at least half of the circumference of said cylindrical portion of the envelope to form an electrical shield for the display elements within the envelope, and connecting means for connecting said layer to the external circuitry 2. The improvement according to claim 1 wherein said connecting means comprises:
a. a conductive spring disposed substantially diametrically within the envelope to contact the electrically conductive layer at two points; and
b. a lead wire connected to said conductive spring and extending through the envelope,

Claims (2)

1. In a symbol display tube including a sealed envelope having a substantially cylindrical portion, a plurality of display elements and means for bombarding said display elements with electrons when said tube is connected to a source of external power and switching circuitry, the improvement comprising: an electrically conductive layer disposed on about at least half of the circumference of said cylindrical portion of the envelope to form an electrical shield for the display elements within the envelope, and connecting means for connecting said layer to the external circuitry
2. The improvement according to claim 1 wherein said connecting means comprises: a. a conductive spring disposed substantially diametrically within the envelope to contact the electrically conductive layer at two points; and b. a lead wire connected to said conductive spring and extending through the envelope.
US827337A 1969-05-23 1969-05-23 Electrically-shielded symbol-display tube Expired - Lifetime US3584252A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US82733769A 1969-05-23 1969-05-23

Publications (1)

Publication Number Publication Date
US3584252A true US3584252A (en) 1971-06-08

Family

ID=25248953

Family Applications (1)

Application Number Title Priority Date Filing Date
US827337A Expired - Lifetime US3584252A (en) 1969-05-23 1969-05-23 Electrically-shielded symbol-display tube

Country Status (4)

Country Link
US (1) US3584252A (en)
DE (1) DE2021767A1 (en)
FR (1) FR2048654A5 (en)
GB (1) GB1254666A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3716899A (en) * 1971-10-13 1973-02-20 Sylvania Electric Prod Vacuum tube readout device having ruggedized internal electrode structure and method of making same
US3780326A (en) * 1971-08-25 1973-12-18 Wagner Electric Corp Symbol display tube with auxiliary electrode
US4004186A (en) * 1975-12-01 1977-01-18 Texas Instruments Incorporated Vacuum fluorescent display having a grid plate coplanar with the anode
US4302706A (en) * 1978-06-22 1981-11-24 Wagner Electric Corporation Glass-to-glass sealing method with conductive layer
US4754199A (en) * 1987-03-04 1988-06-28 Parker William P Self contained gas discharge display device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB234906A (en) * 1924-03-06 1925-06-08 Percie Vaughan Castell Evans Improved method of constructing therimonic valves
US1583414A (en) * 1925-10-31 1926-05-04 Gill Ernest Walter Brudenell Vacuum-tube shield
US2307027A (en) * 1940-05-10 1943-01-05 Davie Shielded radio tube
US2343630A (en) * 1942-04-25 1944-03-07 Du Mont Allen B Lab Inc Shield for cathode ray tubes
US2420311A (en) * 1945-02-10 1947-05-13 Raytheon Mfg Co Conductive shield for external press type electron discharge tubes
US3062980A (en) * 1959-04-28 1962-11-06 Ass Elect Ind Thermionic valves
US3508101A (en) * 1967-03-27 1970-04-21 Ise Electronics Corp Character indicating electron tube

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB234906A (en) * 1924-03-06 1925-06-08 Percie Vaughan Castell Evans Improved method of constructing therimonic valves
US1583414A (en) * 1925-10-31 1926-05-04 Gill Ernest Walter Brudenell Vacuum-tube shield
US2307027A (en) * 1940-05-10 1943-01-05 Davie Shielded radio tube
US2343630A (en) * 1942-04-25 1944-03-07 Du Mont Allen B Lab Inc Shield for cathode ray tubes
US2420311A (en) * 1945-02-10 1947-05-13 Raytheon Mfg Co Conductive shield for external press type electron discharge tubes
US3062980A (en) * 1959-04-28 1962-11-06 Ass Elect Ind Thermionic valves
US3508101A (en) * 1967-03-27 1970-04-21 Ise Electronics Corp Character indicating electron tube

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3780326A (en) * 1971-08-25 1973-12-18 Wagner Electric Corp Symbol display tube with auxiliary electrode
US3716899A (en) * 1971-10-13 1973-02-20 Sylvania Electric Prod Vacuum tube readout device having ruggedized internal electrode structure and method of making same
US4004186A (en) * 1975-12-01 1977-01-18 Texas Instruments Incorporated Vacuum fluorescent display having a grid plate coplanar with the anode
US4302706A (en) * 1978-06-22 1981-11-24 Wagner Electric Corporation Glass-to-glass sealing method with conductive layer
US4754199A (en) * 1987-03-04 1988-06-28 Parker William P Self contained gas discharge display device

Also Published As

Publication number Publication date
GB1254666A (en) 1971-11-24
FR2048654A5 (en) 1971-03-19
DE2021767A1 (en) 1970-12-03

Similar Documents

Publication Publication Date Title
US3278886A (en) Electronic device
US3909655A (en) Cathode ray tube having cylinder with internal resistive helix
GB838078A (en) Thermometer type voltage indicator tube
US3668466A (en) Electron type fluorescent display device with planar adjacent control electrode
US3584252A (en) Electrically-shielded symbol-display tube
US3780326A (en) Symbol display tube with auxiliary electrode
US4053802A (en) High-voltage vacuum tube, particularly an x-ray tube
US3278779A (en) Cathode-ray tube having an insulating spacer between the cathode and the control grid
US3911306A (en) High-voltage vacuum tube, notably an X-ray tube, comprising a metal sleeve
US4503357A (en) Cathode-ray tube
GB1481814A (en) Image intensifier tube device
US3619694A (en) Character-indicating electron tube with fluorescent display structure
GB1141448A (en) Multiple-cathode x-ray triode tube
US3958854A (en) Spark gap apparatus
US2269115A (en) Cathode-ray tube
US3099762A (en) Cathode ray tube using replaceable cathode
US3244923A (en) Character representing glow discharge tube and system for selective excitation of the character representing electrodes thereof
US3258629A (en) Cold cathode display device with fluorescent indicia anodes
GB651012A (en) Improvements in or relating to electric discharge tubes
US2990061A (en) Indicator tube
US4293793A (en) Fluorescent display tube
US3746917A (en) Camera tube with accurate field mesh mounting means
US3153744A (en) Ionization manometer for measuring very low pressure
US2847595A (en) Spring contact high voltage connector
US1945639A (en) Discharge tube

Legal Events

Date Code Title Description
AS Assignment

Owner name: STUDEBAKER-WORTHINGTON, INC., ILLINOIS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WAGNER ELECTRIC CORPORATION;REEL/FRAME:003984/0757

Effective date: 19801229

AS Assignment

Owner name: COOPER INDUSTRIES, INC., 1001 FANNIN, HOUSTON, TEX

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:EDISON INTERNATIONAL, INC., A CORP. OF DE.;REEL/FRAME:004475/0382

Effective date: 19851031