US2834900A - Grid structure - Google Patents

Grid structure Download PDF

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Publication number
US2834900A
US2834900A US607083A US60708356A US2834900A US 2834900 A US2834900 A US 2834900A US 607083 A US607083 A US 607083A US 60708356 A US60708356 A US 60708356A US 2834900 A US2834900 A US 2834900A
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US
United States
Prior art keywords
grid
wires
barrier
barrier grid
dielectric
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
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US607083A
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English (en)
Inventor
John A Mccarthy
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.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE558642D priority Critical patent/BE558642A/xx
Priority to DENDAT1073117D priority patent/DE1073117B/de
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US607083A priority patent/US2834900A/en
Priority to GB24559/57A priority patent/GB815883A/en
Priority to FR1181540D priority patent/FR1181540A/fr
Application granted granted Critical
Publication of US2834900A publication Critical patent/US2834900A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/08—Electrodes intimately associated with a screen on or from which an image or pattern is formed, picked-up, converted or stored, e.g. backing-plates for storage tubes or collecting secondary electrons
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/58—Tubes for storage of image or information pattern or for conversion of definition of television or like images, i.e. having electrical input and electrical output
    • H01J31/60—Tubes for storage of image or information pattern or for conversion of definition of television or like images, i.e. having electrical input and electrical output having means for deflecting, either selectively or sequentially, an electron ray on to separate surface elements of the screen

Definitions

  • the present invention relates to electron discharge apparatus and more particularly to grid structures in cathode ray devices of the type commonly referred to as storage tubes, wherein an input signal is stored in the form of a charge distribution on the insulating surface of a target electrode for a period of time and converted into an output signal at a subsequent time.
  • Barrier grid storage tubes comprise generally, in one form, a target such as a dielectric sheet having a conductive member or backplate, to which the input signal may be applied, in contact with one face thereof, an electron gun for projecting a concentrated electron stream against the other face of the sheet, and a barrier grid adjacent the latter face.
  • a target such as a dielectric sheet having a conductive member or backplate
  • an electron gun for projecting a concentrated electron stream against the other face of the sheet
  • a barrier grid adjacent the latter face In the operation of such a device the beam is deflected in two coordinate directions to impinge any desired discrete area of the dielectric through the barrier grid.
  • the operation involves, basically, two periods or cycles, one store or write and the other remove or read.
  • the backplate potential may be switched between two values, for example, zero and fifty volts.
  • the charging and discharging of the discrete areas above-noted results from emission of secondary electrons from a discrete area when struck by the electron beam.
  • the dielectric surface has a secondary emission ratio greater than unity, so that on the average each electron from the beam will release more the output signal is obtained by detecting the secondary I emission current from the dielectric under the influence of the electron beam with the backplate potential held at one of its values, for example, zero. Reading, or detecting the output signal, may be accomplished either by measuring the net target current or the secondary current alone.
  • Optimum operation of the barrier grid storage tube is dependent to a large extent upon several distinct properties of the barrier grid itself. These properties include high transparency to the electron beam, a grid mesh aperture size which is small in proportion to the electron beam cross section, and a ratio of grid thickness or depth to grid mesh aperture size greater than 0.5.
  • barrier grid structures in the prior art have effected improvements in one or two of these properties, but only at a sacrifice in performance with respect to the remaining properties.
  • One general object of this invention is to improve the performance of cathode ray devices of the storage type. More specifically it is an object of this invention to improve various properties of the barrier grid structure without sacrificing performance due to other properties, thus attaining an overall improvement in barrier grid storage tube performance due to the barrier grid structure.
  • the barrier grid may comprise a thin mesh of interwoven wire having upwards of 400 wires per inch in eachof two mutually perpendicular coordinates.
  • Such a grid provides requisite high transparency to the electron beam in that the extremely fine mesh permits unobstructed passage of more than half of the incident electron beam to the dielectric surface.
  • barrier grid structures also have attained a grid depth to grid aperture size of O.5 or better, which grid property is essential in order to provide a satisfactory electrostatic shield between adjacent portions of the dielectric surface. In this respect it is imperative in the barrier grid tube that redistribution of secondary electrons across the dielectric be prevented.
  • the barrier grid ideally is placed in contact with the dielectric over its entire surface with no spacings through which secondaries might find a way to reach other parts of the to penetrate the barrier grid and be accelerated to the collector.
  • a barrier grid of lower depth to aperture/ size ratio than approximately 0.5 is employed, the positive charges on the dielectric overbalance the barrier grid shielding effect so as to produce excessive redistribution of secondary electrons over adjacent portions of the dielectric, and tube performance is restricted.
  • a barrier grid comprises more than two layers of closely wound wires.
  • the wires in each grid layer are mutually parallel, and the layers are fastened together in such a manner that wires of each grid layer are angularly displaced with respect to the wires of each of the other grid layers lying in parallel planes.
  • the grid structure of a barrier grid storage tube comprise more than two distinct arrays of grid wires.
  • each array comprise mutually parallel grid wires positioned in the same plane.
  • the arrays be assembled in layers wherein the grid wires are positioned in the same or parallel planes.
  • the distinct arrays be mutually angularly disposed.
  • Fig. 1 is a diagrammatic representation of a barrier grid tube incorporating one specific illustrative -'embod1-- ment of this invention.
  • Fig. 2 is a diagrammatic representation of a barrier grid arrangement in accordance with one specific illustrative embodiment of this invention.
  • Pig. 1 depicts an illustrative embodiment of this invention utilizing a barrier
  • the target assembly 20 is a sandwich of three elements including a backplate 22, a dielectric sheet 23, and a .barrier grid 24 positioned in front of the dielectric sheet 23.
  • the dielectric sheet 23 holds an electrostatic charge deposited onits surface by the electron beam for extended periods of time, therebyperforrning the storage function of the tube.
  • the baclcplate 22 is insulated from the barrier grid '24, and its potential may be varied to control the 'chargepattern laid down by the electron beam. The charge deposited .at any discrete area of the dielectric sheet 23 is subsequently detected by returning the electron beam to the discrete area.
  • the particular barrier grid structure employed in this illustrative embodiment of this invention comprises four distinct layers of grid wires lying in parallel planes, each layer comprising a plurality of mutually parallel fine wires. As seen in Fig. 2, each layer is positioned so that wires in adjacent layers are angularlydisplaced; for example, oriented at 45, 90 and 135 with respect to the wires of the other layers.
  • the grid structure in accordance with the illustrative embodiment-of this invention accomplishes all of the necessary :functions ofthe barrier grid to a degree unobtainable by the interwoven two array grid.
  • a particular grid-designed in accordance-withthis illustrative embodiment of this invention comprises four distinct layers of 010003 inch-diameter tungsten wire wound inasingle direction with 5.00 wires per :inch and oriented at 90, 45 and 135, respec'tively, using the grid array closest to the electron gun as a reference axis.
  • the four layers are in contact with each-other and with the dielectric storage surface.
  • the grid is constructed by winding -one array on a frame, rotating the frame 90 and winding a second array. Twosuch frames are fastened together with the wound arrays in physical contact asshown in Fig. '2.
  • barrier grid tube storage of charge on the dielectric surface of a barrier grid tube can only be achieved on those portions of the dielectric which are visible to the electron beam through the barrier grid.
  • a high transparencytothe-electron beam is a desirable property of the barrier grid.
  • the described structure .achievesa transparency of 52 percent, which compares favorably with that of contemporary structures.
  • Uniformity of performance in the barrier grid tube demands a barrier grid having apertures or 'mesh 'open- 7 than when it is centered at 'anintersection of grid wires.
  • The-four layer grid having wires .of adjacent grids angularly displaced as shown in Fig. 2 is superior in performance in this respect to :the two array .grid in-that it presents smaller mesh openings to the incident beam.
  • a ratio of grid depth to grid spacing greater than 0.5 is a necessary property both for minimizing redistribution of secondary electrons and for shielding of the input writing signal.
  • the ratio for the grid struc ture of Fig. 2, dimensioned as described, is greater than 0.6'andis thus highly 'satisfactory'in achieving the-desired e'tfects.
  • a barrier grid storage tube comprising a dielectric target, anelectrode upon one face of said'targct, electron gun means for projecting a stream of electrons against the opposite face of said target, and a multilayer barrier grid'adjacent said opposite face and through which said electrons are projected, said barrier grid comprising four arrays of parallel wires, the wires of each array being oriented at 45, and with respect to the wires of the otherarrays.
  • a barrier grid storage tube comprising a dielectric target, an electrode upon one face of said target, means for projecting an electron beam against the opposite'face of said target, and a multilayer barrier grid in contact with said opposite face and through which said beam is projected, said barrier grid comprising four arrays of parallel wires, the wires of eacharray being oriented at 45, 90 and 135 with respect to the wires of the other arrays.
  • a barrier grid storage tube comprising a dielectric targehan electrode upon one face of said target, electron gun means for projecting an electron beam against the opposite face of said target, and a multilayer barrier grid -in contact with said opposite face and through which said beam is projected, said 'grid'comprising four arrays of parallel wires, and having a ratio of grid depth to grid spacing greater than 0.6.

Landscapes

  • Measurement Of Radiation (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
  • Electron Sources, Ion Sources (AREA)
US607083A 1956-08-30 1956-08-30 Grid structure Expired - Lifetime US2834900A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE558642D BE558642A (de) 1956-08-30
DENDAT1073117D DE1073117B (de) 1956-08-30 (V St A) I Kathodenstrahlrohre mit einer dielektrischen Speicherschicht und mit einer vor der Speicherschicht angeordneten Gitterelektrode
US607083A US2834900A (en) 1956-08-30 1956-08-30 Grid structure
GB24559/57A GB815883A (en) 1956-08-30 1957-08-02 Improvements in or relating to barrier grid storage tubes
FR1181540D FR1181540A (fr) 1956-08-30 1957-08-22 Grille-barrière pour tubes à rayons cathodiques, notamment pour tubes à mémoire

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US607083A US2834900A (en) 1956-08-30 1956-08-30 Grid structure

Publications (1)

Publication Number Publication Date
US2834900A true US2834900A (en) 1958-05-13

Family

ID=24430737

Family Applications (1)

Application Number Title Priority Date Filing Date
US607083A Expired - Lifetime US2834900A (en) 1956-08-30 1956-08-30 Grid structure

Country Status (5)

Country Link
US (1) US2834900A (de)
BE (1) BE558642A (de)
DE (1) DE1073117B (de)
FR (1) FR1181540A (de)
GB (1) GB815883A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3067486A (en) * 1957-06-20 1962-12-11 Itt Target electrode for barrier grid storage tube and method of making same
US3175114A (en) * 1960-05-02 1965-03-23 English Electric Valve Co Ltd Storage cathode ray tubes
US4214025A (en) * 1976-08-25 1980-07-22 English Electric Valve Company Limited Mesh electrodes and method of making them
CN102097265A (zh) * 2010-12-31 2011-06-15 中国航天科技集团公司第五研究院第五一○研究所 一种增强电子束流均匀性的装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1279061B (de) * 1962-05-31 1968-10-03 Westinghouse Electric Corp Fernsehaufnahmeroehre mit Elektronenstrahlabtastung des auf einer lichtempfindlichen Speicherschicht entworfenen Ladungsbildes

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2538836A (en) * 1948-10-15 1951-01-23 Rca Corp Barrier grid storage tube

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE853005C (de) * 1950-07-28 1952-10-20 Rudolf Dr-Ing Hell Fernschreib-Empfangseinrichtung fuer elektrische Impulsuebertragung, vorzugsweise nach dem Fuenfer- oder Siebener-Alphabet

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2538836A (en) * 1948-10-15 1951-01-23 Rca Corp Barrier grid storage tube

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3067486A (en) * 1957-06-20 1962-12-11 Itt Target electrode for barrier grid storage tube and method of making same
US3175114A (en) * 1960-05-02 1965-03-23 English Electric Valve Co Ltd Storage cathode ray tubes
US4214025A (en) * 1976-08-25 1980-07-22 English Electric Valve Company Limited Mesh electrodes and method of making them
CN102097265A (zh) * 2010-12-31 2011-06-15 中国航天科技集团公司第五研究院第五一○研究所 一种增强电子束流均匀性的装置

Also Published As

Publication number Publication date
GB815883A (en) 1959-07-01
BE558642A (de)
DE1073117B (de) 1960-01-14
FR1181540A (fr) 1959-06-16

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