US3303375A - Character display tubes - Google Patents

Character display tubes Download PDF

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Publication number
US3303375A
US3303375A US295333A US29533363A US3303375A US 3303375 A US3303375 A US 3303375A US 295333 A US295333 A US 295333A US 29533363 A US29533363 A US 29533363A US 3303375 A US3303375 A US 3303375A
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US
United States
Prior art keywords
cathode
cup
base
anode
lead
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
US295333A
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English (en)
Inventor
George F Klepp
Olaf H Dalton
Mengel Gaston Pakenham De
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.)
International Standard Electric Corp
Original Assignee
International Standard 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 International Standard Electric Corp filed Critical International Standard Electric Corp
Application granted granted Critical
Publication of US3303375A publication Critical patent/US3303375A/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
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/38—Cold-cathode tubes
    • H01J17/48—Cold-cathode tubes with more than one cathode or anode, e.g. sequence-discharge tube, counting tube, dekatron
    • H01J17/49—Display panels, e.g. with crossed electrodes, e.g. making use of direct current
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0069—Tubes for displaying characters

Definitions

  • the present invention relates to electric glow discharge tubes, having an anode and a plurality of cathodes.
  • the leads may be coated with insulating material, such as alumina, which, however, tends to ake ot or become coated with cathode material due to sputtering.
  • the leads may be completely shrouded by insulating tubes; these have usually to be loosely tting and are allowed a limited degree of longitudinal movement along the leads, in consequence of which they may rattle when in transit and cause customers to think that the tube is detective; furthermore adequate shrouding is diiiicult to achieve and tends to be expensive.
  • a gas filled glow discharge tube having an anode and a plurality of cathode electrodes wherein bare leads to cathode electrodes are spaced between a first and a second structural member of the tube, one of the members being electrically conductive, and wherein the spacing between the leads and each of the two members is less than the minimum sparking distance between them and an anode electrode in the same gaseous atmosphere.
  • an indicator glow discharge tube there is provided a glass envelope with a base at one end and, at the top end, a transparent part to permit viewing of glow discharge display within the tube, the base having lead pins sealed therethrough, and an electrode assembly supported by one or more of the lead pins, the electrode assembly including a metal cup with its base adjacent the base of the envelope, a plurality of spaced apart stacks of ceramic collars Within the cup extending adjacent the cup side walls from the base of the cup towards the top end of the envelope, an aperture through the base of the cup being provided between each stack and the immediately adjacent side wall of the cup, a set of cathodes each shaped for example as a diierent numeral with a pair of projecting ears and mounted by its ears being held between respective pairs ofthe ceramic collars so that the various cathodes lie in respective superimposed planes, and an anode member in the form of a metal mesh extending substantially to the rim of the metal cup over the set of cathodes, an electrical connection between a said lead pin and the
  • FIG. l is a perspective view of an indicator tube according to the invention with parts broken away to show the general construction
  • FIG. 2 is a side view of part of the electrode assembly of the tube of FIG. 1;
  • FIG. 3 is a plan view of the assembly, the cathodes being omitted to simplify the drawing.
  • a glass envelope 1 has at one end a base 2 carrying lead pins 3 sealed through it and, at the other end, a transparent part 4, through which glow discharge display within the tube may be seen.
  • An electrode assembly 5 is mounted on selected ones of the lead pins 3.
  • the assembly 5 includes a generally cylindrical metal cup 6 having a base 7 mounted above and adjacent the envelope base 2 and electrically shielded from it by means of a mica disc 8, which, as shown better in FIG. 2, is somewhat larger than the base of the cup.
  • a plurality of spaced apart stacks of ceramic collars 9 are located within the cup adjacent the side walls and extending from the base of the cup towards a viewing window 4, but more may be provided if desired.
  • the collars are threaded over a metal rod 10 (FIG. 2) which passes through the base of the cup and is joined to one of the lead pins 3.
  • the lowest collar may pass through a close tting aperture in the base of the metal cup and rest upon the mica washer 8, but, in any case, this aperture or a neighbouring one is extended to the rim 0f the cup to afford passage for electrical leads to the electrodes through the base of the cup.
  • the stacks of ceramic collars support a set of cathodes 11 each shaped for example, in the form of a dilierent numeral, a set of numerals 1 to 9 and 0 normally being provided.
  • Each cathode is provided with a pair of projecting ears clamped between respective pairs of ceramic collars on the stacks, the arrangement being such that the numerals lie each in respective superimposed parallel planes below the top end of the tube.
  • the relative sizes of the ceramic collars and the ears are such that the ears are substantially shrouded by the collars so that glow discharge to the ears is prevented.
  • Au anode member in the form of a metal mesh 12 extends over the set of cathodes substantially to the rim of the cup. The mesh may be supported between pairs of ceramic washers at the top of the stacks 9 or may be welded to the metal cup.
  • an additional anode mesh 12a is shown inserted transversely across the set of cathodes about half way up from the base of the cup, but in other embodiments this second anode mesh may be omitted or take some other form than mesh such as an extra numeral.
  • an electrical lead from a respective lead pin 3 is passed through an aperture between one of the stacks of ceramic collars to join an ear of the cathode.
  • the cathodes with their ears and a suitable length of lead may conveniently be made integrally from sheet material so that each lead is in the form of a tape continuous with an ear.
  • the lead is located between the adjacent stack 9 on the one side and the side wall of the anode cup on the other. Connection is made between one of the lead pins and the metal cup and the anode meshes 12 and 12a are connected either to the cup 6 or to a separate lead pin.
  • the tube is filled with a suitable gas at a pressure which, taking into account the separation between the several electrodes, will ensure that, when for a speciiied discharge current a specified potential difference is applied between the anode mesh 12 (and 12a) and any one of the cathodes, cathode glow covers substantially the whole of the numeral-shaped surface of the cathode in question on the side facing the top end of the envelope.
  • the cathode glow at a glow discharge gap is located a short distance away from the cathode surface which is participating the discharge.
  • the greater part of the anode to cathode potential drop is localised between the cathode glow and the cathode.
  • normal glow that is, when the available cathode surface is not completely covered with the glow--the distance between the cathode surface and the glow is equal to the minimum sparking distance for discharge between the cathode and an anode electrode.
  • This distance corresponds to the minimum of the Paschen curve for the gas and electrode materials in question wherein the sparking potential difference is plotted as a function of the product of gas pressure and gap length. If the gap distance is less than the minimum sparking distance, glow discharge cannot be initiated without an increase in voltage. In the case of an existing glow discharge on a neighbouring cathode or portion of the cathode electrode during the normal regime, the area of cathode glow is primarily a function of the glow discharge current and largely independent of voltage. When the whole of the available cathode surface is covered with glow, the effect of an increase in discharge current, for which an increased cathode-anode potential difference is required, is to bring the glow closer to the cathode.
  • the wall of the cup 6 immediately adjacent a stack 9 is. displaced outwardly from the normal cylindrical shape of the remainder of the cup wall 4and the stacks 9 are positioned so that, but for these displaced portions, the cylindrical surface of the cup 6 would intersect them.
  • these displacements Iof the side wall surface provide channels which assist in shielding the cathode leads from the field of other parts of the anode further away from which the -gap length to the leads is greater than the minimum sparking distance.
  • the anode may be formed in one piece, in the embodiment illustrated in FIG. 2 the side wall is crut to provide clearance for the stack of washers 9 and a channel shaped member 13 ⁇ is Welded over the resulting slot. The stack 9 is thus seated partially within the channel shaped member 13.
  • FIG. 2 also shorws a preferred arrangement of Ithe leads coming from out of the stack 9, six leads being shown.
  • two of the 4ceram-ic washers are provided with extension pieces 16 carrying slots, each lead 15 being placed in its own slot.
  • the base of the cup 6 is apertured for passage of the leads.
  • the aperture is provided: in part by Vthe slo-tting of the side wall and the provision of the channels 13.
  • a portion of the mica washer 8 is :also cut away to allow passage of the leads through to the base of the tube.
  • its flanges are cut, one half of each flange being positioned against the inner surface of the wall of Icup 6 and the other on the out-er surface, as is also indicated in FIG. 3.
  • An indicator Iglow discharge tube having a glass envelope with a base at one end, and a transparent part at the top end to permit viewing of glow ydischarge display within the tube, the base having lead pins sealed therethrough, and an electrode assembly supported by the lead pins, the electrode assembly including a metal cup with its base adjacent the base of the envelope and with longitudinal side walls along the length of the envelope, a plurality of sp-aced apart longitudinal stacks of insulating collars within the cup extending adjacent the cupl side walls, a set of cathodes having a plurality of diffeernt shapes, each cathode ybeing supported on said stacks across said tube and mounted between respective pairs of the collars so that the cathodes lie in respective superimposed planes, and an anode member extending across said.
  • each said cathode lead connection being disposed within said channels between the adjacent stack of collars and the cup side wall, 4said stack of collars including a collar hav- 5 6 ing an extension piece extending into said channel por- 2,906,906 9/ 1961 McCauley et a1. 313-2110 X tion, said extension piece having slots for reception of 2,990,061 6/ 1961 McCauley S13- 109.5 said lead connections along the side of said stack. 3,005,922 10/1961 Hart B13-109.5

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Gas-Filled Discharge Tubes (AREA)
US295333A 1962-07-26 1963-07-16 Character display tubes Expired - Lifetime US3303375A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB28770/62A GB1045274A (en) 1962-07-26 1962-07-26 Character display tubes

Publications (1)

Publication Number Publication Date
US3303375A true US3303375A (en) 1967-02-07

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ID=10280872

Family Applications (1)

Application Number Title Priority Date Filing Date
US295333A Expired - Lifetime US3303375A (en) 1962-07-26 1963-07-16 Character display tubes

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Country Link
US (1) US3303375A (de)
CH (1) CH415871A (de)
GB (1) GB1045274A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3562573A (en) * 1967-10-12 1971-02-09 Int Standard Electric Corp Glow suppression in indicator tubes

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1848837A (en) * 1932-03-08 Mounting for flexible conductors
US2219611A (en) * 1937-03-25 1940-10-29 Berghaus Leading-in insulator
US2906906A (en) * 1958-05-22 1959-09-29 Burroughs Corp Indicator tubes
US2990061A (en) * 1960-05-20 1961-06-27 Burroughs Corp Indicator tube
US3005922A (en) * 1959-11-13 1961-10-24 Nat Union Electric Corp Luminous discharge indicia tube

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1848837A (en) * 1932-03-08 Mounting for flexible conductors
US2219611A (en) * 1937-03-25 1940-10-29 Berghaus Leading-in insulator
US2906906A (en) * 1958-05-22 1959-09-29 Burroughs Corp Indicator tubes
US3005922A (en) * 1959-11-13 1961-10-24 Nat Union Electric Corp Luminous discharge indicia tube
US2990061A (en) * 1960-05-20 1961-06-27 Burroughs Corp Indicator tube

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3562573A (en) * 1967-10-12 1971-02-09 Int Standard Electric Corp Glow suppression in indicator tubes

Also Published As

Publication number Publication date
CH415871A (de) 1966-06-30
GB1045274A (en) 1966-10-12

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