US3617803A - Raised-cathode gas discharge indicator having a sputter shield - Google Patents

Raised-cathode gas discharge indicator having a sputter shield Download PDF

Info

Publication number
US3617803A
US3617803A US876618A US3617803DA US3617803A US 3617803 A US3617803 A US 3617803A US 876618 A US876618 A US 876618A US 3617803D A US3617803D A US 3617803DA US 3617803 A US3617803 A US 3617803A
Authority
US
United States
Prior art keywords
substrate
cathode
pins
pin
diameter
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
US876618A
Inventor
James W Wheeler
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.)
WALTER E HELLER WESTERN Inc
Sperry Corp
Microsemi Corp Power Management Group
Original Assignee
Sperry Rand 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 Sperry Rand Corp filed Critical Sperry Rand Corp
Application granted granted Critical
Publication of US3617803A publication Critical patent/US3617803A/en
Assigned to EMERSON ELECTRIC CO., A MO CORP. reassignment EMERSON ELECTRIC CO., A MO CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BECKMAN INSTRUMENTS, INC.
Assigned to BECKMAN INDUSTRIAL CORPORATION A CORP OF DE reassignment BECKMAN INDUSTRIAL CORPORATION A CORP OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: EMERSON ELECTRIC CO., A CORP OF MO
Assigned to WALTER E HELLER WESTERN INCORPORATED reassignment WALTER E HELLER WESTERN INCORPORATED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: DIXON DEVELOPMENT, INC. A CORP. OF CA.
Assigned to DIXON DEVELOPMENT, INC., A CA CORP. reassignment DIXON DEVELOPMENT, INC., A CA CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BECKMAN INDUSTRIAL CORPORATION
Assigned to BABCOCK DISPLAY PRODUCTS,INC. reassignment BABCOCK DISPLAY PRODUCTS,INC. CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE OCT.12,1984 Assignors: DIXION DEVELOPMENT,INC.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00Gas-filled discharge tubes with solid cathode
    • H01J17/38Cold-cathode tubes
    • H01J17/48Cold-cathode tubes with more than one cathode or anode, e.g. sequence-discharge tube, counting tube, dekatron
    • H01J17/49Display panels, e.g. with crossed electrodes, e.g. making use of direct current
    • H01J17/491Display panels, e.g. with crossed electrodes, e.g. making use of direct current with electrodes arranged side by side and substantially in the same plane, e.g. for displaying alphanumeric characters

Definitions

  • a gas discharge indicating device comprising a plurality of symbol-forming cathode elements disposed intermediate a cathode-supporting substrate and a transparent anode connected to one another in a manner to form a hermetically sealed enclosure for containing an ionizable gas, the cathode elements being supported in spaced relation to both the anode and substrate on pins passing through the latter.
  • An insulating shield is provided on each support pin proximate the substrate preferably in noncontacting relation therewith.
  • This invention relates to symbol indicators of the gas discharge type wherein symbols are represented by localized glow discharges between an anode member and selectively energized cathode elements of a plurality of such elements arranged to form various symbols. More, particularly, the invention relates to means for preventing or at least inhibiting the development of sputter-induced shorting contacts between individual cathode elements.
  • That application relates to a gas discharge indicator comprising a cathode-supporting substrate overlaid by a transparent anode member to form a hermetically sealed enclosure containing ionizable gas.
  • the cathode elements are supported in spaced relation to both the anode and the cathode-supporting substrate on pins passing through the substrate.
  • Glow discharges representative of the symbols to be presented are produced by energizing appropriate cathode elements.
  • the spacing of the cathode elements relative to both the anode and cathode-supporting substrate minimizes sputtering from the substrate side of the cathodes for a prescribed operating pressure of the ionizable gas in the hermetically sealed enclosure. This feature of reduced sputtering in combination with depressions formed in the interior surface of the substrate in the region of the pins passing therethrough retards the development of sputtered shorting contacts between the individual support pll'lS.
  • the present invention is also directed to apparatus for reducing the formation of sputter-induced shorting contacts between the respective cathode-supporting pins of a raisedcathode gas discharge indicator, particularly in the depressed region of the substrate around or near the cathode supporting pins.
  • an insulating shield typically a nonconductive washer, is placed on each cathode support proximate the substrate and preferably in nonconducting relation therewith. This configuration provides a means for protecting the depression around the cathode support pins from sputtered products although it will be understood that the shield of the present invention may be usefully employed in arrangements which do not include the depressions.
  • FIG. 1 is a simplified exploded view in perspective of a typical embodiment of the invention.
  • FIG. 2 is a section along line 2-2 of FIG. 1.
  • glass substrate 1 is apertured to receive a number of electrical contacting pins 2 which are hermetically sealed to the substrate.
  • the pins extend beyond both surfaces of the substrate so as to be adapted, at the ends beyond the rear surface of the substrate, for connection to a mating pin receptacle (not shown).
  • individual cathode segments 3 are secured to the other end of the respective pins, for example, by welding, to form a conventional alpha-numeric symbol.
  • the lengths of the individual pins are adjusted so that all of the cathode segments lie in approximately the same plane at substantially the same distance from substrate 1. it should be noted that additional symbols and other configurations can obviously be provided, if desired, simply by modifying the number, shape or position of the cathode segments and their associated contacting pins.
  • Substrate l is also provided with an aperture 4 to which gas fill tube 5 is hermetically sealed on the side of the substrate opposite the cathode segments.
  • a mercury ampule 6 is inserted inside tube 5.
  • substrate 1 is equipped with an additional pair of hermetically sealed feed through pins 7 and 8 for establishing electrical contact to the anode member 9 of the gas discharge tube.
  • the anode member comprises a glass substrate on which is deposited a thin film 10 of a transparent conductive material completely covering the interior surface facing substrate 1.
  • Anode member 9 is spaced from substrate 1 by glass spacer plate 11 having a main aperture 12 defining a volume for enclosing and ionizable gas to produce cathode glows when the indicator is completely assembled and energized.
  • Spring contacts 13 and 14 pass through a pair of apertures l5 and 16 to establish electrical contact from pins 7 and 8 to the conducting film surface 10 in the assembled unit.
  • the thickness of the spacer plate 11 is determined by the anodecathode and cathode-substrate spacings required to cause only the anode side of the cathode elements to glow under a given gas pressure, taking into account, of course, the thickness of the cathode elements themselves.
  • the spacer thickness is typically 0.040 inch and the cathode segments are spaced from the interior surface 17 of substrate 1 by approximately 0.005 inch.
  • the spacing of the cathode segments from the cathodesupporting substrate can be obtained as explained in the aforementioned Armstrong et al. application by first inserting the pins 2 through substrate 1 so that the ends to be attached to the cathode segments lie flush with the interior surface of the substrate, then hermetically sealing the pins to the substrate and finally etching the interior surface of the substrate to the desired depth. The process is so controlled that a depression 19 is formed in the substrate surrounding the pins.
  • a suitable etchant is a solution of distilled water and hydrofluoric acid.
  • the cathode segments can be spaced from the substrate by adjusting the cathode-supporting lengths thereabove by any conventional mechanical technique.
  • insulating washers 18 are slid over the pins and maintained thereon a short distance above the substrate, typically 0.001 inch to 0.003 inch in the illustrated embodiment as by gluing or by means of an abutment or shoulder on the pins.
  • Any material suitable for use in the ionizable gas, such as glass, ceramic, mica or ceramic insulated metals, can be used for the washers.
  • the washer thickness is'not critical.
  • washers having a thickness in the range of 0.001 to 0.006 inch have a thickness in the range of 0.001 to 0.006 inch, but there is no apparent reason why thicknesses outside of this range would not also be suitable.
  • the washer diameter must be suitable to isolate the desired area around each pin in a manner to achieve the aforedescribed mode of operation.
  • a washer having a diameter of 0.060 inch, for example, has been found appropriate for use with a pin having a diameter of 0.020 inch.
  • the washers should preferably have a diameter such that the difference between the washer diameter and pin diameter is at least twice as great as the separation between the support substrate and the cathode elements.
  • the indicator is assembled by bringing elements 1, 9 and 1 1 into aligned contact with each other and hermetically sealing the entire edge surface of the aligned unit.
  • Conventional techniques are applied for purging the atmosphere within the sealed unit and then filling and sealing the unit with an appropriate ionizable gasand the mercury contained in ampule 6.
  • the mercury is released into the sealed gas atmosphere at a suitable time during fabrication as is well known in the art to provide therein an amount of this vapor to inhibit cathode sputtering by absorbing a significant amount of kinetic energy of the ionized gas particles before they bombard the cathode segments.
  • construction of a gas discharge indicator in the described manner will essentially eliminate sputtering from the substrate side of the cathode segments, Moreover, sputtered material emanating from the anode side thereof will be effectively blocked by the washers to preclude the formation of shorting contacts between the individual support pins along the interior surface of substrate 1 thereby significantly lengthening the operational life of the indicator. Sputtered material may tend to collect on the upper surface 20 of the washer but electrical contact with the substrate will not be likely since differential temperature expansion and vibration of the various components will prevent the establishment of any permanent low-resistance connection therebetween.
  • a gas discharge indicator comprising a hermetically sealed envelope containing an ionizable gas at glow discharge pressure, said envelope being formed at least in part by a cathode-supporting substrate,
  • each of the pins passing through and hermetically sealed to the substrate such that one end of each of the pins extends beyond the interior surface of the substrate, the opposite end of each of the pins being adapted for connection to a source of electrical excitation for selectively energizing the respective pins,
  • each support pin in closely spaced noncontacting relation with the interior surface of the substrate for further inhibiting deposition of sputter material adjacent each pin.
  • the insulating washer members have a diameter such that the difference between the insulating member diameter and the pin diameter is at least a factor of two greater than the cathode-to-substrate spacing.

Landscapes

  • Gas-Filled Discharge Tubes (AREA)

Abstract

A gas discharge indicating device comprising a plurality of symbol-forming cathode elements disposed intermediate a cathodesupporting substrate and a transparent anode connected to one another in a manner to form a hermetically sealed enclosure for containing an ionizable gas, the cathode elements being supported in spaced relation to both the anode and substrate on pins passing through the latter. An insulating shield is provided on each support pin proximate the substrate preferably in noncontacting relation therewith. Under appropriate conditions of gas pressure and anode-cathode and cathode-substrate spacing, localized glow discharges between the anode and selectively energized cathodes are confined to the regions therebetween, resulting in minimized sputtering from the substrate side of the cathode. This feature in combination with the insulating shields operates to preclude sputtered shorting contacts from developing between the respective support pins in the region of the substrate.

Description

United States Patent Inventor James W. Wheeler Scottsdale, Ariz.
Appl. No. 876,618
Filed Nov. 14, 1969 Patented Nov. 2, 1971 Assignee Sperry Rand Corporation RAISED-CATHODE GAS DISCHARGE INDICATOR Primary Examiner-Raymond F. Hossfeld Attorney-S. C. Yeaton ABSTRACT: A gas discharge indicating device comprising a plurality of symbol-forming cathode elements disposed intermediate a cathode-supporting substrate and a transparent anode connected to one another in a manner to form a hermetically sealed enclosure for containing an ionizable gas, the cathode elements being supported in spaced relation to both the anode and substrate on pins passing through the latter. An insulating shield is provided on each support pin proximate the substrate preferably in noncontacting relation therewith. Under appropriate conditions of gas pressure and anodecathode and cathode-substrate spacing, localized glow discharges between the anode and selectively energized cathodes are confined to the regions therebetween, resulting in minimized sputtering from the substrate side of the cathode, This feature in combination with the insulating shields operates to preclude sputtered shorting contacts from developing between the respective support pins in the region of the substrate RAISED-CATIIODE GAS DISCHARGE INDICATOR HAVING A SPUTTER SHIELD BACKGROUND OF THE INVENTION 1. Field of the invention I This invention relates to symbol indicators of the gas discharge type wherein symbols are represented by localized glow discharges between an anode member and selectively energized cathode elements of a plurality of such elements arranged to form various symbols. More, particularly, the invention relates to means for preventing or at least inhibiting the development of sputter-induced shorting contacts between individual cathode elements.
2. Description of the Prior Art it has been observed heretofore that sputter-induced shorting contacts tend to form between cathode elements most readily along the surface of the cathode substrate in gas discharge indicator devices similar to those shown in the appended figures. Accordingly, a recent innovation in such indicator devices provided for the symbol-forming cathode elements to be spaced from the cathode-supporting substrate so as to permit the inclusion of means for inhibiting the formation of shorting contacts along the surface of the substrate. A prior art gas discharge indicator of this type is disclosed in US. application Ser. No. 742,662, filed July 5, 1968, in the name of James B. Armstrong et al. and assigned to the assignee of the present invention. That application relates to a gas discharge indicator comprising a cathode-supporting substrate overlaid by a transparent anode member to form a hermetically sealed enclosure containing ionizable gas. The cathode elements are supported in spaced relation to both the anode and the cathode-supporting substrate on pins passing through the substrate. Glow discharges representative of the symbols to be presented are produced by energizing appropriate cathode elements. As explained in the Armstrong et al. application, the spacing of the cathode elements relative to both the anode and cathode-supporting substrate minimizes sputtering from the substrate side of the cathodes for a prescribed operating pressure of the ionizable gas in the hermetically sealed enclosure. This feature of reduced sputtering in combination with depressions formed in the interior surface of the substrate in the region of the pins passing therethrough retards the development of sputtered shorting contacts between the individual support pll'lS.
SUMMARY OF THE INVENTION The present invention is also directed to apparatus for reducing the formation of sputter-induced shorting contacts between the respective cathode-supporting pins of a raisedcathode gas discharge indicator, particularly in the depressed region of the substrate around or near the cathode supporting pins. in contradistinction to the aforementioned Armstrong et al. application, an insulating shield, typically a nonconductive washer, is placed on each cathode support proximate the substrate and preferably in nonconducting relation therewith. This configuration provides a means for protecting the depression around the cathode support pins from sputtered products although it will be understood that the shield of the present invention may be usefully employed in arrangements which do not include the depressions.
The rationale for the improvement provided by the structure of the present invention is as follows. Metallic ions dislodged or sputtered from the cathode as a consequence of bombardment by particles of the ionizable gas travel along relatively straight paths until they strike another particle or some internal structural component of the indicator tube whereupon they are redirected along another relatively straight path. By virtue of the insulating washers having a comparatively large diameter relative to that of the support pins and further being mounted thereon in close proximity to the substrate, accessibility of the sputtered ions to the surface regions of the substrate immediately adjacent the individual sup port pins is substantially decreased. Moreover, any ions which succeed in reading these regions are restricted to paths at shallow angles relative to the substrate surface. Under such conditions, the ability of the ions to penetrate into the depressions is significantly diminished.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified exploded view in perspective of a typical embodiment of the invention.
FIG. 2 is a section along line 2-2 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the FlGS., glass substrate 1 is apertured to receive a number of electrical contacting pins 2 which are hermetically sealed to the substrate. The pins extend beyond both surfaces of the substrate so as to be adapted, at the ends beyond the rear surface of the substrate, for connection to a mating pin receptacle (not shown). individual cathode segments 3 are secured to the other end of the respective pins, for example, by welding, to form a conventional alpha-numeric symbol. The lengths of the individual pins are adjusted so that all of the cathode segments lie in approximately the same plane at substantially the same distance from substrate 1. it should be noted that additional symbols and other configurations can obviously be provided, if desired, simply by modifying the number, shape or position of the cathode segments and their associated contacting pins.
Substrate l, is also provided with an aperture 4 to which gas fill tube 5 is hermetically sealed on the side of the substrate opposite the cathode segments. A mercury ampule 6 is inserted inside tube 5. Further, substrate 1 is equipped with an additional pair of hermetically sealed feed through pins 7 and 8 for establishing electrical contact to the anode member 9 of the gas discharge tube. The anode member comprises a glass substrate on which is deposited a thin film 10 of a transparent conductive material completely covering the interior surface facing substrate 1. Anode member 9 is spaced from substrate 1 by glass spacer plate 11 having a main aperture 12 defining a volume for enclosing and ionizable gas to produce cathode glows when the indicator is completely assembled and energized. Spring contacts 13 and 14 pass through a pair of apertures l5 and 16 to establish electrical contact from pins 7 and 8 to the conducting film surface 10 in the assembled unit. The thickness of the spacer plate 11 is determined by the anodecathode and cathode-substrate spacings required to cause only the anode side of the cathode elements to glow under a given gas pressure, taking into account, of course, the thickness of the cathode elements themselves.
in the illustrated embodiment, the spacer thickness is typically 0.040 inch and the cathode segments are spaced from the interior surface 17 of substrate 1 by approximately 0.005 inch. The spacing of the cathode segments from the cathodesupporting substrate can be obtained as explained in the aforementioned Armstrong et al. application by first inserting the pins 2 through substrate 1 so that the ends to be attached to the cathode segments lie flush with the interior surface of the substrate, then hermetically sealing the pins to the substrate and finally etching the interior surface of the substrate to the desired depth. The process is so controlled that a depression 19 is formed in the substrate surrounding the pins. A suitable etchant is a solution of distilled water and hydrofluoric acid. Alternatively, the cathode segments can be spaced from the substrate by adjusting the cathode-supporting lengths thereabove by any conventional mechanical technique. After the cathode-supporting ends of the pins have been elevated above the interior surface of the substrate, insulating washers 18 are slid over the pins and maintained thereon a short distance above the substrate, typically 0.001 inch to 0.003 inch in the illustrated embodiment as by gluing or by means of an abutment or shoulder on the pins. Any material suitable for use in the ionizable gas, such as glass, ceramic, mica or ceramic insulated metals, can be used for the washers. The washer thickness is'not critical. Satisfactory operation has been obtained with washers having a thickness in the range of 0.001 to 0.006 inch, but there is no apparent reason why thicknesses outside of this range would not also be suitable. The washer diameter, however, must be suitable to isolate the desired area around each pin in a manner to achieve the aforedescribed mode of operation. A washer having a diameter of 0.060 inch, for example, has been found appropriate for use with a pin having a diameter of 0.020 inch. in addition the washers should preferably have a diameter such that the difference between the washer diameter and pin diameter is at least twice as great as the separation between the support substrate and the cathode elements.
The indicator is assembled by bringing elements 1, 9 and 1 1 into aligned contact with each other and hermetically sealing the entire edge surface of the aligned unit. Conventional techniques are applied for purging the atmosphere within the sealed unit and then filling and sealing the unit with an appropriate ionizable gasand the mercury contained in ampule 6. The mercury is released into the sealed gas atmosphere at a suitable time during fabrication as is well known in the art to provide therein an amount of this vapor to inhibit cathode sputtering by absorbing a significant amount of kinetic energy of the ionized gas particles before they bombard the cathode segments. I
As hereinbefore explained, construction of a gas discharge indicator in the described manner will essentially eliminate sputtering from the substrate side of the cathode segments, Moreover, sputtered material emanating from the anode side thereof will be effectively blocked by the washers to preclude the formation of shorting contacts between the individual support pins along the interior surface of substrate 1 thereby significantly lengthening the operational life of the indicator. Sputtered material may tend to collect on the upper surface 20 of the washer but electrical contact with the substrate will not be likely since differential temperature expansion and vibration of the various components will prevent the establishment of any permanent low-resistance connection therebetween.
While the invention has been described in its preferred embodiment, it is to be understood that the words which have been used are words of description rather than limitation and that changes may be made without departing from the true scope and spirit of the invention in its broader aspects.
1 claim:
1. A gas discharge indicator comprising a hermetically sealed envelope containing an ionizable gas at glow discharge pressure, said envelope being formed at least in part by a cathode-supporting substrate,
a plurality of electrical-contacting cathode support pins passing through and hermetically sealed to the substrate such that one end of each of the pins extends beyond the interior surface of the substrate, the opposite end of each of the pins being adapted for connection to a source of electrical excitation for selectively energizing the respective pins,
a'plurality of cathode segments attached to the pin ends internal to the envelope whereby said segments are spaced from the interior surface of said substrate, and the segments being arranged so as to provide for the presentation of desired symbols,
anode means supported in spaced relation with respect to said cathode segments,
a depression formed in the interior surface of said substrate around each of the support pins for inhibiting deposition of cathode sputter material on said substrate in the region of each pin, and
an insulating washer member concentrically mounted on each support pin in closely spaced noncontacting relation with the interior surface of the substrate for further inhibiting deposition of sputter material adjacent each pin.
2. The apparatus of claim 1 wherein the insulating washer members have a diameter greater than the diameter of said depressions for acting in combination therewith to inhibit sputter material deposition ad'acent each support pin.
3. The apparatus of claim wherein the insulating washer members have a diameter such that the difference between the insulating member diameter and the pin diameter is at least a factor of two greater than the cathode-to-substrate spacing.
l II

Claims (3)

1. A gas discharge indicator comprising a hermetically sealed envelope containing an ionizable gas at glow discharge pressure, said envelope being formed at least in part by a cathodesupporting substrate, a plurality of electrical-contacting cathode support pins passing through and hermetically sealed to the substrate such that one end of each of the pins extends beyond the interior surface of the substrate, the opposite end of each of the pins being adapted for connection to a source of electrical excitation for selectively energizing the respective pins, a plurality of cathode segments attached to the pin ends internal to the envelope whereby said segments are spaced from the interior surface of said substrate, and the segments being arranged so as to provide for the presentation of desired symbols, anode means supported in spaced relation with respect to said cathode segments, a depression formed in the interior surface of said substrate around each of the support pins for inhibiting deposition of cathode sputter material on said substrate in the region of each pin, and an insulating washer member concentrically mounted on each support pin in closely spaced noncontacting relation with the interior surface of the substrate for further inhibiting deposition of sputter material adjacent each pin.
2. The apparatus of claim 1 wherein the insulating washer members have a diameter greater than the diameter of said depressions for acting in combination therewith to inhibit sputter material deposition adjacent each support pin.
3. The apparatus of claim 2 wherein the insulating washer members have a diameter such that the difference between the insulating member diameter and the pin diameter is at least a factor of two greater than the cathode-to-substrate spacing.
US876618A 1969-11-14 1969-11-14 Raised-cathode gas discharge indicator having a sputter shield Expired - Lifetime US3617803A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US87661869A 1969-11-14 1969-11-14

Publications (1)

Publication Number Publication Date
US3617803A true US3617803A (en) 1971-11-02

Family

ID=25368169

Family Applications (1)

Application Number Title Priority Date Filing Date
US876618A Expired - Lifetime US3617803A (en) 1969-11-14 1969-11-14 Raised-cathode gas discharge indicator having a sputter shield

Country Status (1)

Country Link
US (1) US3617803A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3704386A (en) * 1971-03-19 1972-11-28 Burroughs Corp Display panel and method of operating said panel to produce different colors of light output
US3716742A (en) * 1970-03-03 1973-02-13 Fujitsu Ltd Display device utilization gas discharge

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3716742A (en) * 1970-03-03 1973-02-13 Fujitsu Ltd Display device utilization gas discharge
US3704386A (en) * 1971-03-19 1972-11-28 Burroughs Corp Display panel and method of operating said panel to produce different colors of light output

Similar Documents

Publication Publication Date Title
US7456634B2 (en) Method and apparatus for shielding feedthrough pin insulators in an ionization gauge operating in harsh environments
KR900003310B1 (en) Ion producing apparatus
US3260880A (en) Electro-optical indicator devices with multiple anodes for each cell
US4518894A (en) Display panel having memory
US2991387A (en) Indicator tube
US3675065A (en) Planar gas discharge indicator
US3701918A (en) Gaseous-flow, discharge display device with an array of hollow cathodes
US3526584A (en) Method of providing a field free region above a substrate during sputter-depositing thereon
US2876374A (en) Electronic tube structures
US3617803A (en) Raised-cathode gas discharge indicator having a sputter shield
US3346759A (en) Planar array of cathode and anode electrodes installed in channels for visual indicator display device
US3675066A (en) Planar raised cathode alpha-numeric gas discharge indicator
US4322656A (en) Spacer mount in a gas-discharge display device
US2878407A (en) Ion control means
US3806752A (en) Planar raised cathode alpha-numeric gas discharge indicator
US3872339A (en) Multi-position character display panel
US3580654A (en) Method of making display devices
US3701916A (en) Display panel having gas-filled cells utilizing phosphor materials
US3947713A (en) Mercury capsule assembly for display panel
US3849694A (en) Multiple position display panel having spurious glow suppressor
US3821584A (en) Gas filled display device having mercury inlet shield
EP0057315B1 (en) Segment display system and method of operating same
US3849693A (en) Multiple position display panel having segmented electrodes
US3684909A (en) Display panel having particle source
US4464135A (en) Method of making a display panel

Legal Events

Date Code Title Description
AS Assignment

Owner name: BECKMAN INDUSTRIAL CORPORATION A CORP OF DE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:EMERSON ELECTRIC CO., A CORP OF MO;REEL/FRAME:004328/0659

Effective date: 19840425

Owner name: EMERSON ELECTRIC CO., A MO CORP.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BECKMAN INSTRUMENTS, INC.;REEL/FRAME:004319/0695

Effective date: 19840301

AS Assignment

Owner name: DIXON DEVELOPMENT, INC., A CA CORP.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BECKMAN INDUSTRIAL CORPORATION;REEL/FRAME:004337/0564

Effective date: 19840928

Owner name: WALTER E HELLER WESTERN INCORPORATED

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DIXON DEVELOPMENT, INC. A CORP. OF CA.;REEL/FRAME:004337/0572

Effective date: 19840928

AS Assignment

Owner name: BABCOCK DISPLAY PRODUCTS,INC.

Free format text: CHANGE OF NAME;ASSIGNOR:DIXION DEVELOPMENT,INC.;REEL/FRAME:004372/0199

Effective date: 19841002