US2757303A - Damp rod construction for cathode-ray tube grid structures - Google Patents

Damp rod construction for cathode-ray tube grid structures Download PDF

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Publication number
US2757303A
US2757303A US424071A US42407154A US2757303A US 2757303 A US2757303 A US 2757303A US 424071 A US424071 A US 424071A US 42407154 A US42407154 A US 42407154A US 2757303 A US2757303 A US 2757303A
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United States
Prior art keywords
wires
grid
rod
damp
cathode
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Expired - Lifetime
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US424071A
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English (en)
Inventor
Silverman Louis
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Chromatic Television Laboratories Inc
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Chromatic Television Laboratories Inc
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Publication date
Priority to NL196371D priority Critical patent/NL196371A/xx
Priority to BE537449D priority patent/BE537449A/xx
Application filed by Chromatic Television Laboratories Inc filed Critical Chromatic Television Laboratories Inc
Priority to US424071A priority patent/US2757303A/en
Priority to DEC11087A priority patent/DE955868C/de
Priority to FR1122784D priority patent/FR1122784A/fr
Priority to GB11104/55A priority patent/GB769744A/en
Application granted granted Critical
Publication of US2757303A publication Critical patent/US2757303A/en
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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
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/80—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching
    • H01J29/803—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching for post-acceleration or post-deflection, e.g. for colour switching

Definitions

  • the present invention relates to cathode-ray tubes of the type adapted to effect the reconstitution of polychrome images. More particularly, the invention relates to cathode-ray tubes having a grid of essentially coplanar Wires positioned adjacent to a striped phosphor screen or target electrode.
  • Cathode-ray tubes constructed with a grid of essentially coplanar wires located adjacent to a striped phosphor screen are already known in the art, and may serve to focus the beam electrons into a pattern of thin lines registered with the phosphor strips of the screen.
  • the PDF (post-defiectiomfocusing) type of cathode-ray tube operation has already been set forth and explained by Ernest 0. Lawrence in various of his United States patent applications, of which Serial No. 219,213, filed April 4, 1951., (now U. S. Patent No. 2,692,532, granted October 26, 1954), is illustrative.
  • the tube may incorporate a screen, or target electrode, made up of a relatively large number of very narrow component-color phosphor strips laid down in a predetermined sequence and intended to luminesce, when impacted by the cathode-ray beam, in colors such as red, green, blue, green, red, green, and so on.
  • a grid assembly is located adjacent to such phosphor screen.
  • the grid may be made up of essentially coplanar wires, and so related to the phosphor strips that, in an electron-optical sense, there is a wire aligned with each blue strip and similarly a wire aligned with each red strip.
  • the red wires are connected to a common terminal, while the blue wires are similarly joined together electrically.
  • the beam electrons may be focused by the above-described lens structure into a series of lines registered with the phosphor strips. If there is a zero potential difference between the red and blue terminals of the wire grid, then these lines formed by the beam electrons may be caused to lie within the boundaries of the green strips. If the wires associated with the red strips are made positive relative to the wires electronoptically related to the blue strips, the beam electrons will be deflected, and the thin lines will now lie within the boundaries of the red strips. Similarly, the electrons will strike the blue strips when the wires associated with such strips are relatively positive with respect to the red wires. Different component colors are thus displayed according to the potential difference (if any) existing between the two sections of the grid wire assembly.
  • D the diameter of the damp rod then there will be good surface contact between the rod and each of the grid wires with which it is interwoven.
  • each of the damp rods is interleaved not only with the grid wires but also with each adjoining damp rod.
  • the construction accordingly is one in which any selected rod, for example, overlies those particular grid wires which the two adjoining damp rods go under.
  • the material of which the damp rods are composed is preferably of a vitreous nature.
  • One substance which has been found to be especially suitable for the purpose of the Patterson case is what is known commercially as G12 glass.
  • the damp rods made of any particular substance are homogeneous throughout.
  • One object of the present invention is to provide an improved form of cathode-ray tube suitable for the reconstitution of polychrome images.
  • a further object of the invention is to substantially completely overcome, in a polychrome cathode-ray tube having a grid structure of essentially coplanar wires, any tendency toward vibration the wires of the grid structure may possess either when color-changing potentials are cyclically applied thereto or when the grid structure is subjected to shocks of a physical and/or electrical nature.
  • An additional object of the present invention is to accomplish the above objective while at the same time maintaining the coplanar relationship of the grid wires.
  • a still further object of the present invention is to provide, in a polychrome cathode-ray tube having a colorcontrol grid structure of essentially coplanar wires, at least one damping element, of non-linear configuration and of non-homogeneous cross-section, interwoven with the wires of the color-control grid.
  • An additional object of the present invention is to provide a damping element of the above nature the surface of which is formed of insulating material and the core of which is metallic.
  • Figure 1 is a partly schematic representation of one form of cathode-ray tube in which the present invention may be incorporated;
  • Figure 2 is an enlarged view of a portion of Figure 1;
  • Figure 3 is a perspective view of a portion of the wire grid assembly of Figure 1, showing in greater detail the interwoven relationship between the grid wires and the damp rods;
  • Figure 4 is a sectional view of a portion of Figure 3 along the line 44;
  • Figure 5 is a plan view of a portion of Figure 3, showing one preferred association of the grid wires and phosphor strips; and Figure 6 is an enlarged perspective view of one of the damp rods showing the inner construction thereof.
  • FIG. 10 there is generally indicated by the reference numeral 10 one type of cathode-ray tube in which the present invention may be incorporated.
  • This tube includes the usual components for developing a beam 12 of electrons and for deflecting this electron beam in substantially mutually perpendicular directions so as to trace a raster on the tube target electrode.
  • the target electrode of tube 10 for ease of illustration, is disclosed as forming part of a separate unit or assembly 14 mounted in any suitable manner adjacent to the transparent end wall 16 of the tube. Obviously, however, the end wall 16 when suitably configured may itself comprise the target electrode if convenient or desirable.
  • the assembly 14 reference is made to above-mentioned Vale U. S. Patent No. 2,721,288, as well as to further applications of Renn Zaphiropoulos, Serial No. 307,435 and Serial No. 307,436, concurrently filed September 2, 1952 now respectively U. S. Patents No. 2,683,833, granted July 13, 1954 and No. 738,436, granted March 13, 1956.
  • the assembly 14 (which includes a transparent base plate 18, a phosphor coating 20 thereon, and a grid of essentially parallel color-control conductors 22 adjacent to the phosphor coating 20) is positioned and supported within the tube 10 so that the light produced by impingement of the scanning beam 12 on the phosphor coating 20 may be viewed by an observer through the transparent end wall 16 of the cathode-ray tube.
  • the base plate 18 may be of glass or other suitable material.
  • the phosphor coating 20 is preferably in the form of a plurality of narrow strips which have the property of fiuorescing in difierent component colors of the image to be reconstituted, these colors, for example, being red, green, and blue.
  • the strips are laid down side-byside in a predetermined chromatic sequence. As best shown in Figures 3 and 4, the order chosen for illustration is red, green, blue, green, red, green, and so on. This order, however, forms no specific part of the present invention, but is suggested as one sequence which has proven to be satisfactory in practice.
  • the phosphor coating 20 is aluminized or otherwise provided with a thin film of electrically-conductive material on the surface toward the source of the impinging electrons.
  • the color-control grid adjacent to the target surface 20 is composed of a plurality of linear conductors, such as the parallel wires 22, aligned with the phosphor strips in a manner best shown in Figures 3 and 5.
  • a small section of the striped phosphor surface 29 of the target electrode is illustrated in Figure 3 in order to permit a clear showing of the grid wire relationships.
  • each pair of wires may, in an electron-optical sense, be considered subtending strip areas constituting one color cycle.
  • a potential is applied to the conductive coating on the phosphor surface 20 which is relatively positive with respect to the average, of D.-C. potential of the wires 22 of the grid assembly.
  • This gives rise to a plurality of cylindrical electrostatic lenses, which serve to focus the electrons of the scanning beam 12 into a series of fine lines registered with the phosphor strips.
  • the present invention is obviously applicable to cases where the wires 22 serve either as a color-changing device alone, as will subsequently appear, or as an electrostatic lens assembly per se.
  • any suitable method may be employed for positioning the Wires 22 so that they are adjacent to the phosphor-coated surface 20 of the target electrode, a pair of bars 24 and 26 is shown, each of these bars having on its upper surface a series of equally-spaced grooves for aligning the wires 22 and preventing lateral movement thereof at such points.
  • the wires are respectively held taut (as best shown in Figures 1 and 2) by a plurality of hooks forming part of two retaining assemblies 28 secured to the under surface of the transparent base plate 18 beyond the boundaries of the image raster area.
  • This general type of construction is described and claimed in the Zaphiropoulos U. S. Patent No. 2,683,833, referred to above.
  • one of the principal features of the present invention consists in substantially completely overcoming any tendency toward vibration the wires of a color-control grid assembly of the class described may possess by interweaving one of more rigid rod-like members of a non-homogeneous nature between the wires of the color control assembly, while at the same time retaining the coplanar wire relationship.
  • One such arrangement is shown in Figures 1 through 5.
  • each of the damp rods 30, 32, and 34 may be, for convenience of description, termed zig-zag in nature.
  • an essentially linear rod is bent at points corresponding in number to the number of grid wires with which the rod is to be interwoven, with the direction of bending being the same at alternate points.
  • the rod configuration which results is undulating in character, with the amount of bending being just sufficient so that good contact is maintained between the zig-zagged damp rod and the grid wires with which it is interwoven, while at the same time avoiding any displacement of the latter from their normal coplanar position.
  • Adjacent damp rods contact diiferent sections of the same grid wire. This is particularly brought out in Figure 5, which shows the rod 32, for example, overlying those particular grid Wires which the rods 30 and 34 go under. Also, in Figure 4, the side view of rods 30 and 32 brings out that the former (which lies in back of the rod 32) contacts each grid wire at a point which is diametrically opposed to the point at which each grid wire is contacted by the rod 32.
  • the rod 34 although shown in Figure 4, would occupy a position relatively similar to that of the rod 30.
  • the all-ceramic damp rods are preferably of a diameter be tween .003 and .005", or in other words between 3 and 5 mils. This size has been found to be especially suitable in actual tube constructions. Glass rods of such small diameter obviously have relatively little strength, and consequently, as stated above, the problem of breakage of the damp rods has been a serious one.
  • a damp rod formed in accordance with the teaching of the present invention is illustrated in Figure 6.
  • This damp rod comprises a wire of, say, between one and two mils diameter (preferably composed of some such material as molybdenum or tungsten) which is provided with a very thin coating of an electrically-insulating substance such as Alundum.
  • vitreous enamel may also be applied as a coating to wire composed of tungsten, molybdenum or aluminum.
  • a satisfactory coating may be applied by standard commercial processes such as are well known in the manufacture of filaments for electron receiving tubes.
  • the wire is first zig-zagged, and then the insulating coating applied so that the coated wire has a final diameter in the neighborhood of the three to five mil limit set forth by Patterson.
  • a damp rod exhibits very much greater resistance to breakage than does the all-ceramic damp rod previously employed.
  • damp rods such as described herein are of great advantage in either single-gun or multiple-gun cathode-ray tubes in order to reduce the amplitude of any vibratory action induced by sudden changes in potential difference between the grid wire assembly as a whole and the conductive coating of the phosphor screen. This may take place, for example, when there is an arcing or flash-over between the wire grid and phosphor screen, causing the grid wires to be suddenly released from the position to which they had been drawn by the attraction of the positively-charged screen.
  • the damp rods of the present disclosure are especially efiective in preventing this vibratory action from reaching an amplitude where it might cause color contamination in the reproduced image, or, in severe cases, actual fusion of the grid wires of a single-gun tube when the displacement is so great that adjacent wires are brought into contact with one another.
  • a vibration-inhibiting element for a cathode-ray tube designed for the reconstitution of polychrome images and having a grid structure of essentially coplanar wires lying between the cathode-ray beam developing means of said tube and the target electrode scanned thereby and substantially adjacent to the target, said vibration-inhibiting element comprising a non-linear rod having a metallic core surrounded by a substance having the properties of an electrical insulator, extending substantially transversely to the parallel wires of said grid structure and interwoven therebetween in such a manner as to retain a coplanar wire relationship.
  • a vibration-inhibiting element in which the electrical insulating substance surrounding said metallic core is Alundum.
  • a vibration-inhibiting element in which the electrical insulating substance surrounding said metallic core is in the nature of a vitreous enamel.
  • a vibration-inhibiting assembly for a cathode-ray tube designed for the reconstitution of polychrome im ages, said tube having a planar-surfaced target electrode and a grid structure of essentially coplanar wires lying adjacent to the planar surface of said target electrode, said vibration-inhibiting assembly including a plurality of rod-like members of zig-zag configuration, each extending substantially transversely to the wires of said grid structure and interwoven therebetween the zig-zag configuration of each of the said rod-like members being such that the interweaving of each said member with the Wires of said grid structure results in the former contacting each of the said grid wires and at the same time substantially retains the said coplanar grid wire relationship, each said rod-like member having a surface portion which possesses insulating properties and a core portion which is composed of metallic material, thereby causing each said rod-like member to exhibit a relatively high resistance to breakage under any stress to which it may be subjected.
  • a zig-zag damp rod for inhibiting vibration of the linear conductors of a grid structure forming part of a cathode-ray tube designed for the production of polychrome irnages, said linear conductors lying adjacent to the target electrode of said cathode-ray tube, said damp rod being essentially of a linear nature but being bent in-and-out at points substantially corresponding in number to the number of linear conductors making up said grid structure, the direction of bending of said damp rod being the same at alternate points, so that the said bent rod is substantially symmetrical about its longitudinal axis, said damp rod having a surface area composed of material which acts as an electrical insulator and a metallic core.
  • a color-control grid structure of parallel wires arranged in coplanar relation in a plane adjacent to the target electrode of said cathode-ray tube, and at least one rod-like element having a metal core and a coating of insulating material, said one rod-like element being respectively bent inand-out at equally-spaced points corresponding in number essentially to the number of parallel wires making up said grid structure, said rod-like element being interwoven with the said parallel wires without disturbing the coplanar relationship of the latter, whereby the tendency of said wires to vibrate when color-control potentials are applied to said grid structure will be strongly inhibited, and whereby the tendency of said rod-like element to break as a result of physical shocks applied thereto will be strongly resisted by the metallic material making up said core.
  • a vibration-inhibiting element for a cathode-ray tube designed for the reconstitution of polychrome images and having a grid structure of parallel coplanar wires lying between the cathode-ray beam developing means of said tube and the target electrode scanned thereby and substantially adjacent to the target, said vibrationinhibiting element comprising a non-linear rod extending substantially transversely to the parallel wires of said grid structure and interwoven therebetween to contact said wires but in such a manner as to retain the coplanar wire relationship, said non-linear rod being formed of metal having a coating of insulating material on at least that portion of its surface which is in contact with the parallel wires of said grid structure.

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  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
US424071A 1954-04-19 1954-04-19 Damp rod construction for cathode-ray tube grid structures Expired - Lifetime US2757303A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
NL196371D NL196371A (enrdf_load_stackoverflow) 1954-04-19
BE537449D BE537449A (enrdf_load_stackoverflow) 1954-04-19
US424071A US2757303A (en) 1954-04-19 1954-04-19 Damp rod construction for cathode-ray tube grid structures
DEC11087A DE955868C (de) 1954-04-19 1955-04-16 Elektronenstrahlroehre zur Wiedergabe von Farbfernsehbildern
FR1122784D FR1122784A (fr) 1954-04-19 1955-04-18 Tube cathodique, approprié à la reproduction d'images de télévision en couleurs
GB11104/55A GB769744A (en) 1954-04-19 1955-04-18 Improvements in or relating to cathode-ray tubes for use in reproducing colour television pictures

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US424071A US2757303A (en) 1954-04-19 1954-04-19 Damp rod construction for cathode-ray tube grid structures

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US2757303A true US2757303A (en) 1956-07-31

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US (1) US2757303A (enrdf_load_stackoverflow)
BE (1) BE537449A (enrdf_load_stackoverflow)
DE (1) DE955868C (enrdf_load_stackoverflow)
FR (1) FR1122784A (enrdf_load_stackoverflow)
GB (1) GB769744A (enrdf_load_stackoverflow)
NL (1) NL196371A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2796546A (en) * 1953-06-29 1957-06-18 Chromatic Television Lab Inc Damp rod construction for cathode ray tube grid structure
US2905845A (en) * 1955-09-27 1959-09-22 Owens Illinois Glass Co Full vision cathode ray tubes
US2913613A (en) * 1956-08-03 1959-11-17 Gen Electric Electrode structure for color cathode ray tube
US2930918A (en) * 1957-10-16 1960-03-29 Gen Electric High damping twisted wire
US3487253A (en) * 1967-08-28 1969-12-30 Us Army Mechanical damping of planar vacuum tube grids
US5369330A (en) * 1991-06-13 1994-11-29 Nec Corporation Damp rod construction for CRT grid structures
US5394051A (en) * 1992-12-28 1995-02-28 Zenith Electronics Corporation Vibration-damping configuration in a strip shadow mask

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1149383B (de) * 1961-05-19 1963-05-30 Siemens Ag Farbbildroehre mit Paralleldraht-Gitter

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1572726A (en) * 1922-08-31 1926-02-09 Western Electric Co Electron-discharge device
US1930563A (en) * 1931-02-02 1933-10-17 Radiotechnique Electronic discharge tube
US2072638A (en) * 1934-01-30 1937-03-02 Telefunken Gmbh Electrode mounting for discharge tubes
US2416056A (en) * 1944-02-21 1947-02-18 Heinz E Kallmann Raster screen
US2446791A (en) * 1946-06-11 1948-08-10 Rca Corp Color television tube
US2461515A (en) * 1945-07-16 1949-02-15 Arthur B Bronwell Color television system
US2568448A (en) * 1947-09-23 1951-09-18 Gen Electric Parallax correction in color television

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE529971A (enrdf_load_stackoverflow) * 1953-06-29

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1572726A (en) * 1922-08-31 1926-02-09 Western Electric Co Electron-discharge device
US1930563A (en) * 1931-02-02 1933-10-17 Radiotechnique Electronic discharge tube
US2072638A (en) * 1934-01-30 1937-03-02 Telefunken Gmbh Electrode mounting for discharge tubes
US2416056A (en) * 1944-02-21 1947-02-18 Heinz E Kallmann Raster screen
US2461515A (en) * 1945-07-16 1949-02-15 Arthur B Bronwell Color television system
US2446791A (en) * 1946-06-11 1948-08-10 Rca Corp Color television tube
US2568448A (en) * 1947-09-23 1951-09-18 Gen Electric Parallax correction in color television

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2796546A (en) * 1953-06-29 1957-06-18 Chromatic Television Lab Inc Damp rod construction for cathode ray tube grid structure
US2905845A (en) * 1955-09-27 1959-09-22 Owens Illinois Glass Co Full vision cathode ray tubes
US2913613A (en) * 1956-08-03 1959-11-17 Gen Electric Electrode structure for color cathode ray tube
US2930918A (en) * 1957-10-16 1960-03-29 Gen Electric High damping twisted wire
US3487253A (en) * 1967-08-28 1969-12-30 Us Army Mechanical damping of planar vacuum tube grids
US5369330A (en) * 1991-06-13 1994-11-29 Nec Corporation Damp rod construction for CRT grid structures
US5394051A (en) * 1992-12-28 1995-02-28 Zenith Electronics Corporation Vibration-damping configuration in a strip shadow mask

Also Published As

Publication number Publication date
DE955868C (de) 1957-01-10
BE537449A (enrdf_load_stackoverflow)
NL196371A (enrdf_load_stackoverflow)
FR1122784A (fr) 1956-09-12
GB769744A (en) 1957-03-13

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