US3580654A - Method of making display devices - Google Patents

Method of making display devices Download PDF

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US3580654A
US3580654A US764983A US3580654DA US3580654A US 3580654 A US3580654 A US 3580654A US 764983 A US764983 A US 764983A US 3580654D A US3580654D A US 3580654DA US 3580654 A US3580654 A US 3580654A
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tubulation
vaporizable material
capsule
envelope
cells
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US764983A
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George A Kupsky
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Unisys Corp
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Burroughs Corp
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Assigned to BURROUGHS CORPORATION reassignment BURROUGHS CORPORATION MERGER (SEE DOCUMENT FOR DETAILS). DELAWARE EFFECTIVE MAY 30, 1982. Assignors: BURROUGHS CORPORATION A CORP OF MI (MERGED INTO), BURROUGHS DELAWARE INCORPORATED A DE CORP. (CHANGED TO)
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    • 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
    • H01J9/38—Exhausting, degassing, filling, or cleaning vessels
    • H01J9/395—Filling vessels
    • 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
    • H01J9/24—Manufacture or joining of vessels, leading-in conductors or bases
    • H01J9/26—Sealing together parts of vessels
    • H01J9/261—Sealing together parts of vessels the vessel being for a flat panel display

Definitions

  • the material is freed from the capsule, and, with the entire assembly heated to a suitable temperature to cause the anitsputtering agent to enter the working area of the device, the tubulation is sealed off at an area close to the device itself and with the capsule within the portion of the tubulation which is removed.
  • the mercury is provided in a capsule which carries a heating wire and is permanently mounted within the tube with the heating wire connected to two tube pins.
  • the mcrcury is released from the capsule at a desired stage in the manufacturing process by means of heat generated by current flow through the heating wire.
  • the mercury is released, its vapor readily fills the tube envelope.
  • tube pins are provided for an anode, for each of ten cathodes, and for two decimal points, and, in addition, two extra tube pins are required for connection to the capsule heating wire.
  • space must be available inside the envelope for the mercury capsule.
  • a display device of the flat panel type which includes a large number of tiny cells formed in a unitary panel and utilizing cold cathodes and gaseous glow.
  • These devices use a gas of the type described above, and, in addition, require mercury to minimize cathode sputtering.
  • known procedures for introducing the gases and for introducing the mercury are not satisfactory. For example, pins are not available for providing heating current for a capsule, and space is not available in the device for a mercury capsule.
  • the invention comprises a method making a gas discharge display device including the steps of assembling the parts of the device, baking out the device, introducing an ionizable gas into the device aging the electrodes of the device, introducing an antisputtering agent which has relatively high molecular weight and vaporization temperature, treating the device to cause the anitsputtering agent to vaporize and enter all portions of the device, and then sealing the device.
  • FIG. I is a perspective view of a display device prepared according to the invention.
  • FIG. 2 is a sideview of the device of FIG. I and apparatus used in the manufacture thereof.
  • a display device embodying the invention shown in FIG. I, includes a central plate of insulating material such as glass or ceramic which is provided with rows and columns of apertures or cells 30.
  • Top and bottom glass cover plates 40 and 50 are secured to the center plate 20 with parallel row electrodes 60 between bottom'plate 50 and plate 20, and parallel column electrodes 70 between top plate 40 and center plate 20.
  • Each row electrode 60 is aligned with a row of cells 30, and each column electrode 70 is aligned with a column of cells 30, and a cell is located at each crossing of a row electrode and a column electrode.
  • the row electrodes 60 are cathodes, and the column electrodes are anodes.
  • Plates 20, 40, and 50 are preferably rectangular, and the-row and column conductors 60 and 70 extend beyond the edges of the plates so that electrical connection can be made to them.
  • the central plate 20 is about 1 mm. in thickness
  • the top and bottom plates are about I to 3 mm. in thickness
  • the cells are about 0.04 inch in diameter at a density of about twelve cells per linear inch.
  • the conductors 60 and 70 are about 0.05 inch wide and about 5 mils thick.
  • the various glass plates are provided with plate 40 carrying a glass tubulation in which is positioned a small glass capsule which contains a tiny droplet of mercury 92.
  • the capsule 90 is supported by a wire conductor 100 which is wrapped around it and has its ends extending through the wall of the capsule for subsequent connection outside the capsule to a source of power 106.
  • the various plates are sealed together along their edges by means of a glass frit or the like to provide a gastight seal.
  • the panel is pumped out and baked out by way of the tubulation 80, and it is filled with a gas suitable for sustaining cathode glow.
  • Gases such as argon and neon are suitable, with one satisfactory gas mixture comprising about 5 percent argon, percent neon, and a trace of krypton.
  • the gas pressure is in the range of about 40 to about 80 Torr at room temperature.
  • the tubulation 80 is sealed off below the mercury capsule as at 120.
  • the panel is then aged by cyclically firing each of the rows of cells in order, with about 50 to about ma. of current flowing per row of cells. This aging step is carried out for a few hours.
  • the mercury is released from its capsule 90 by means of heat applied to the capsule to cause it to crack and release the mercury.
  • the necessary heat is generated by current flow in conductor 100.
  • the mercury initially deposits on the wall of the tubulation above the capsule 90, and, according to the invention, in order to force the mercury into all of the cells 30 of the panel, the panel is baked in an oven at about 200 C. for several hours. With the panel held at this temperature, the portion of the tubulation containing the mercury capsule is removed, and the tubulation is sealed off at 130. The first aging step is then repeated.
  • the device 10 may be heated to about 200 C. before the mercury is released from its capsule, and then when the mercury is released, it travels into the cells 30 directly without first condensing in the tubulation.
  • the capsule 90 could be made of metal, and it could be heated by induction. It could also be of a material which can absorb infrared radiation, such radiation then being used for heating and breaking the capsule. Other modifications may also be made within the scope of the invention.
  • a method of manufacturing a display tube of the type including a plurality of relatively small gas-filled cells comprising the steps of mounting and enclosing electrodes within an envelope having an exhaust tubulation, the electrodes having portions associated with each of said cells,
  • step of placing a supply of vaporizable material in the tubulation involves placing a sealed capsule containing the vaporizable material together with an attached wire in said tubulation, and wherein the step of activating said vaporizable material involves passing a current through said attached wire to heat the enclosed vaporizable material and crack said capsule.

Abstract

A method of making a gas discharge display device comprising assembling the component parts of the device and providing a tabulation through which the device can be filled with the desired gas. A capsule containing an antisputtering agent such as mercury is mounted within the tabulation, along with suitable means by which it may be heated. The device is suitably baked out and otherwise preliminarily processed; the desired gas is introduced; and the tubulation is sealed off with the capsule remaining therein. After any other processing steps are carried out as required, the material is freed from the capsule, and, with the entire assembly heated to a suitable temperature to cause the anitsputtering agent to enter the working area of the device, the tubulation is sealed off at an area close to the device itself and with the capsule within the portion of the tubulation which is removed.

Description

United States Patent [72] Inventor George A. Kupsky Miliord,N.J. [21] Appl. No. 764,983 [22] Filed Oct. 2, 1968 [45] Patented May 25, 1971 [73] Assignee Burroughs Corporation Detroit, Mich.
(54} METHOD OF MAKING DISPLAY DEVICES 6 Claims, 2 Drawing Figs.
[52] US. Cl 316/20, 316/24 [51] lnt.Cl H0lj 9/38 [50] Field of Search 316/20, 24, 26,17, 18; 141/59 [56] References Cited UNITED STATES PATENTS 1,565,579 12/1925 Mac Rae 316/20X 1,826,383 10/1931 Smalley..... 316/20X 1,841,034 1/1932 lves 316/20X 2,449,493 9/1948 Longini 316/20X 2,755,159 7/1956 Bemuretal. 2,991,387 7/1961 McCawley ABSTRACT: A method of making a gas discharge display device comprising assembling the component parts of the device and providing a tabulation through which the device can be filled with the desired gas. A capsule containing an antisputtering agent such as mercury is mounted within the tabulation, along with suitable means by which it may be heated. The device is suitably baked out and otherwise preliminarily processed; the desired gas is introduced; and the tubulation is sealed 0E with the capsule remaining therein. After any other processing steps are carried out as required, the material is freed from the capsule, and, with the entire assembly heated to a suitable temperature to cause the anitsputtering agent to enter the working area of the device, the tubulation is sealed off at an area close to the device itself and with the capsule within the portion of the tubulation which is removed.
PATENTEU m2 5 19m INVENTOR. GEORGE A. KUPSKY mm gig ATTORNEY METHOD OF MAKING DISPLAY DEVICES BACKGROUND OF THE INVENTION It has become standard practice in cold cathode display devices to utilize argon and neon and the like as the preferred medium for providing glow discharge, and, ever since .I. H. McCauleys invention, it has become good practice, in addition, to provide a small quantity of mercury vapor to minimize cathode sputtering. Display tubes of the type having relatively large envelopes which contain relatively large cathode characters such as numerals, letters, or the like, have utilized these features and have become commercially successful. In tubes of this type, the mercury is provided in a capsule which carries a heating wire and is permanently mounted within the tube with the heating wire connected to two tube pins. The mcrcury is released from the capsule at a desired stage in the manufacturing process by means of heat generated by current flow through the heating wire. When the mercury is released, its vapor readily fills the tube envelope. In this type of tube, tube pins are provided for an anode, for each of ten cathodes, and for two decimal points, and, in addition, two extra tube pins are required for connection to the capsule heating wire. Moreover, space must be available inside the envelope for the mercury capsule.
For a long time, there has been a need for a display device of the flat panel type which includes a large number of tiny cells formed in a unitary panel and utilizing cold cathodes and gaseous glow. These devices use a gas of the type described above, and, in addition, require mercury to minimize cathode sputtering. However, because of the type of construction used in these devices and because of the small size of the cells, known procedures for introducing the gases and for introducing the mercury are not satisfactory. For example, pins are not available for providing heating current for a capsule, and space is not available in the device for a mercury capsule.
SUMMARY OF THE INVENTION Briefly, the invention comprises a method making a gas discharge display device including the steps of assembling the parts of the device, baking out the device, introducing an ionizable gas into the device aging the electrodes of the device, introducing an antisputtering agent which has relatively high molecular weight and vaporization temperature, treating the device to cause the anitsputtering agent to vaporize and enter all portions of the device, and then sealing the device.
DESCRIPTION OF THE DRAWING FIG. I is a perspective view of a display device prepared according to the invention; and
FIG. 2 is a sideview of the device of FIG. I and apparatus used in the manufacture thereof.
DESCRIPTION OF THE-PREFERRED EMBODIMENTS The principles of the invention are applicable to display devices of different types. However, for purposes of illustration, only one type of device, a flat panel device, is shown and described. Panel devices of this type are illustrated in detail in a concurrently filed application of G. A. Kupsky.
A display device embodying the invention, shown in FIG. I, includes a central plate of insulating material such as glass or ceramic which is provided with rows and columns of apertures or cells 30. Top and bottom glass cover plates 40 and 50 are secured to the center plate 20 with parallel row electrodes 60 between bottom'plate 50 and plate 20, and parallel column electrodes 70 between top plate 40 and center plate 20. Each row electrode 60 is aligned with a row of cells 30, and each column electrode 70 is aligned with a column of cells 30, and a cell is located at each crossing of a row electrode and a column electrode. In device I0, the row electrodes 60 are cathodes, and the column electrodes are anodes. Plates 20, 40, and 50 are preferably rectangular, and the-row and column conductors 60 and 70 extend beyond the edges of the plates so that electrical connection can be made to them.
In one typical panel 10, the central plate 20 is about 1 mm. in thickness, the top and bottom plates are about I to 3 mm. in thickness, and the cells are about 0.04 inch in diameter at a density of about twelve cells per linear inch. The conductors 60 and 70 are about 0.05 inch wide and about 5 mils thick.
In manufacturing device 10, the various glass plates are provided with plate 40 carrying a glass tubulation in which is positioned a small glass capsule which contains a tiny droplet of mercury 92. The capsule 90 is supported by a wire conductor 100 which is wrapped around it and has its ends extending through the wall of the capsule for subsequent connection outside the capsule to a source of power 106.
With the glass plates and electrodes assembled and held together mechanically, the various plates are sealed together along their edges by means of a glass frit or the like to provide a gastight seal.
Next, the panel is pumped out and baked out by way of the tubulation 80, and it is filled with a gas suitable for sustaining cathode glow. Gases such as argon and neon are suitable, with one satisfactory gas mixture comprising about 5 percent argon, percent neon, and a trace of krypton. The gas pressure is in the range of about 40 to about 80 Torr at room temperature. After the panel is baked out and then filled with its gas, the tubulation 80 is sealed off below the mercury capsule as at 120. The panel is then aged by cyclically firing each of the rows of cells in order, with about 50 to about ma. of current flowing per row of cells. This aging step is carried out for a few hours.
Next, the mercury is released from its capsule 90 by means of heat applied to the capsule to cause it to crack and release the mercury. The necessary heat is generated by current flow in conductor 100. If the device 10 is not at an elevated temperature, the mercury initially deposits on the wall of the tubulation above the capsule 90, and, according to the invention, in order to force the mercury into all of the cells 30 of the panel, the panel is baked in an oven at about 200 C. for several hours. With the panel held at this temperature, the portion of the tubulation containing the mercury capsule is removed, and the tubulation is sealed off at 130. The first aging step is then repeated.
If desired in the foregoing process, the device 10 may be heated to about 200 C. before the mercury is released from its capsule, and then when the mercury is released, it travels into the cells 30 directly without first condensing in the tubulation.
It is customary to use two or more aging steps with gas devices as described; however, this is not a requirement and one step could be used.
It will be clear to those skilled in the art that the capsule 90 could be made of metal, and it could be heated by induction. It could also be of a material which can absorb infrared radiation, such radiation then being used for heating and breaking the capsule. Other modifications may also be made within the scope of the invention.
1 claim:
1. A method of manufacturing a display tube of the type including a plurality of relatively small gas-filled cells comprising the steps of mounting and enclosing electrodes within an envelope having an exhaust tubulation, the electrodes having portions associated with each of said cells,
placing a supply of vaporizable material at a point within said tubulation, said material being physically immobilized and prevented from vaporizing and entering said tubulation and said tube during the processing steps associated with assembling said tube,
exhausting the atmosphere of said envelope through said tubulation,
inserting a gas into said envelope,
sealing said tubulation beyond the point where said vaporizable material is located,
releasing said vaporizable material into said tubulation, and
heating said envelope and said tubulation to cause the vapor of said material to penetrate into said cells.
2. The method set forth in claim 1 further including the step of removing the tubulation beyond the point of the second seal and also removing the remainder of the vaporizable material.
3. The method set forth in claim 1 wherein the step of placing a supply of vaporizable material in the tubulation involves placing a sealed capsule containing the vaporizable material together with an attached wire in said tubulation, and wherein the step of activating said vaporizable material involves passing a current through said attached wire to heat the enclosed vaporizable material and crack said capsule.
4. The method defined in claim 1 and including, at a convenient time after sealing said tubulation, the step of aging said tube by applying voltages to said electrodes according to a predetermined program. v
5. The method defined in claim 1 and including the step of sealing said tubulation a second time at a region between said envelope and the point at which said vaporizable material was originally placed.
6. The method defined in claim 1 wherein said vaporizable material is mercury.

Claims (6)

1. A method of manufacturing a display tube of the type including a plurality of relatively small gas-filled cells comprising the steps of mounting and enclosing electrodes within an envelope having an exhaust tubulation, the electrodes having portions associated with each of said cells, placing a supply of vaporizable material at a point within said tubulation, said material being physically immobilized and prevented from vaporizing and entering said tubulation and said tube during the processing steps associated with assembling said tube, exhausting the atmosphere of said envelope through said tubulation, inserting a gas into said envelope, sealing said tubulation beyond the point where said vaporizable material is located, releasing said vaporizable material into said tubulation, and heating said envelope and said tubulation to cause the vapor of said material to penetrate into said cells.
2. The method set forth in claim 1 further including the step of removing the tubulation beyond the point of the second seal and also removing the remainder of the vaporizable material.
3. The method set forth in claim 1 wherein the step of placing a supply of vaporizable material in the tubulation involves placing a sealed capsule containing the vaporizable material together with an attached wire in said tubulation, and wherein the step of activating said vaporizable material involves passing a current through said attached wire to heat the enclosed vaporizable material and crack said capsule.
4. The method defined in claim 1 and including, at a convenient time after sealing said tubulation, the step of aging said tube by applying voltages to said electrodes according to a predetermined program.
5. The method defined in claim 1 and including the step of sealing said tubulation a second time at a region between said envelope and the point at which said vaporizable material was originally placed.
6. The method defined in claim 1 wherein said vaporizable material is mercury.
US764983A 1968-10-02 1968-10-02 Method of making display devices Expired - Lifetime US3580654A (en)

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BR (1) BR6912969D0 (en)
CH (1) CH506178A (en)
DE (1) DE1949112A1 (en)
FR (1) FR2019657A1 (en)
GB (1) GB1240068A (en)
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3913999A (en) * 1972-08-11 1975-10-21 Thorn Electrical Ind Ltd Manufacturing electric devices having sealed envelopes
EP0004750A2 (en) * 1978-03-31 1979-10-17 Thorn Emi Plc Method of an arrangement for introducing dosing material into the envelope of a gas discharge lamp
US4317062A (en) * 1979-08-06 1982-02-23 Beckman Instruments, Inc. Valve means and mercury reservoir for gas discharge display
US5952775A (en) * 1994-06-09 1999-09-14 Canon Kabushiki Kaisha Image-forming apparatus having vent tubes
US20030141815A1 (en) * 2002-01-25 2003-07-31 Jae-Sang Chung Method for removing impurities of plasma display panel
US20080174227A1 (en) * 2002-10-17 2008-07-24 Canon Kabushiki Kaisha Gas Measuring Method Inside a Sealed Container

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1565579A (en) * 1921-07-28 1925-12-15 Westinghouse Lamp Co Method of introducing getter materials into incandescent lamps
US1826383A (en) * 1926-05-01 1931-10-06 Claude Neon Lights Inc Method and apparatus for introducing foreign substances into vacuum tube lights
US1841034A (en) * 1928-12-21 1932-01-12 Western Electric Co Electrooptical apparatus
US2449493A (en) * 1947-08-28 1948-09-14 Westinghouse Electric Corp Attaining high vacuum in photoelectric tubes
US2755159A (en) * 1953-05-19 1956-07-17 Sylvania Electric Prod Vapor filling process for discharge lamps
US2991387A (en) * 1958-09-22 1961-07-04 Burroughs Corp Indicator tube

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1565579A (en) * 1921-07-28 1925-12-15 Westinghouse Lamp Co Method of introducing getter materials into incandescent lamps
US1826383A (en) * 1926-05-01 1931-10-06 Claude Neon Lights Inc Method and apparatus for introducing foreign substances into vacuum tube lights
US1841034A (en) * 1928-12-21 1932-01-12 Western Electric Co Electrooptical apparatus
US2449493A (en) * 1947-08-28 1948-09-14 Westinghouse Electric Corp Attaining high vacuum in photoelectric tubes
US2755159A (en) * 1953-05-19 1956-07-17 Sylvania Electric Prod Vapor filling process for discharge lamps
US2991387A (en) * 1958-09-22 1961-07-04 Burroughs Corp Indicator tube

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3913999A (en) * 1972-08-11 1975-10-21 Thorn Electrical Ind Ltd Manufacturing electric devices having sealed envelopes
EP0004750A2 (en) * 1978-03-31 1979-10-17 Thorn Emi Plc Method of an arrangement for introducing dosing material into the envelope of a gas discharge lamp
EP0004750A3 (en) * 1978-03-31 1979-10-31 Thorn Emi Limited Heating of dosing capsule
US4317062A (en) * 1979-08-06 1982-02-23 Beckman Instruments, Inc. Valve means and mercury reservoir for gas discharge display
US5952775A (en) * 1994-06-09 1999-09-14 Canon Kabushiki Kaisha Image-forming apparatus having vent tubes
US6867537B2 (en) 1994-06-09 2005-03-15 Canon Kabushiki Kaisha Image-forming apparatus having vent tube and getter
US20030141815A1 (en) * 2002-01-25 2003-07-31 Jae-Sang Chung Method for removing impurities of plasma display panel
US20080174227A1 (en) * 2002-10-17 2008-07-24 Canon Kabushiki Kaisha Gas Measuring Method Inside a Sealed Container
US7679279B2 (en) * 2002-10-17 2010-03-16 Canon Kabushiki Kaisha Image display device having a sealed container with an exhaust pipe

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DE1949112A1 (en) 1970-04-16
FR2019657A1 (en) 1970-07-03
NO127724B (en) 1973-08-06
GB1240068A (en) 1971-07-21
BR6912969D0 (en) 1973-01-02
NL6914476A (en) 1970-04-06
CH506178A (en) 1971-04-15
BE739670A (en) 1970-03-16

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Free format text: MERGER;ASSIGNORS:BURROUGHS CORPORATION A CORP OF MI (MERGED INTO);BURROUGHS DELAWARE INCORPORATEDA DE CORP. (CHANGED TO);REEL/FRAME:004312/0324

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