US2490731A - Electron beam control apparatus - Google Patents

Electron beam control apparatus Download PDF

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Publication number
US2490731A
US2490731A US729421A US72942147A US2490731A US 2490731 A US2490731 A US 2490731A US 729421 A US729421 A US 729421A US 72942147 A US72942147 A US 72942147A US 2490731 A US2490731 A US 2490731A
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tube
coils
ring
coil
focussing
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Elmer D Goodale
Otto H Schade
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RCA Corp
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RCA Corp
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    • 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
    • H01J31/26—Image pick-up tubes having an input of visible light and electric output
    • H01J31/28—Image pick-up tubes having an input of visible light and electric output with electron ray scanning the image screen
    • H01J31/34—Image pick-up tubes having an input of visible light and electric output with electron ray scanning the image screen having regulation of screen potential at cathode potential, e.g. orthicon
    • H01J31/36—Tubes with image amplification section, e.g. image-orthicon
    • 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
    • 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
    • H01J31/26—Image pick-up tubes having an input of visible light and electric output
    • H01J31/28—Image pick-up tubes having an input of visible light and electric output with electron ray scanning the image screen

Definitions

  • This invention in general relates to devices and apparatus for focussing and deflecting an electron beam, and more particularly to such apparatus as is especially adaptable for use in iocussing and deflecting the cathode ray beam in the socalled low velocity beam scanning cathode ray image pick up or camera tubes, such as those known as the orthicon and/ or image orthicon, for instance.
  • the image section of the image orthicon type tube contains, among other elements, a semi-transparent photocathode on the inside of the tube end wall, an accelerator electrode, and a target which consists of a thin glass disc with a fine mesh screen very closely spaced to it on the photocathode side. Focussing in the image section is accomplished by means of a magnetic field produced by external coils and by varying the photocathode voltage.
  • Light from the scene being televised is picked up by an optical lens system and focussed onto the photocathode which emits photoelectrons from each illuminated area in proportion to the intensity of the light striking the area.
  • the photoelectrons released upon the light image being focussed upon the photosensitive cathode are focussed on the target by means of developed magnetic fields which function in conjunction with the tube. Electrostatic accelerating fields move the electrons between the photoelectric other side; by. conductivity through the glass in a time that cathode and the target disc and provide the initial focussing effect.
  • the opposite side of the glass target from that onwhich the charges are formed is scanned by a low velocity electron beam produced by the electron gun of the tube.
  • the beam is focussed at the-target by a magnetic field produced by focussing coils positioned externally to the tube, as well as by the electrostatic field produced due to-voltage differences between certain electrodes withinthe tube.
  • a declerating electrode to create a field for decelerating the electrons of the electron beam just prior to their approach to the target.
  • the electrons stop their forward motion at the surface of the glass target.
  • Those electrons not required to neutralizethe charges in the target are then influenced -by the-fields within the tube and are caused to turn back toward the source and then are collected and focussed onto a multi-stage electron multiplier, except when the beam approaches the positively charged portions of the pattern a on theglass target.
  • the electrons are deposited from the scanning beam-or absorbed from the scanning beam in quantitiesisufficient to neutralize the charge pattern on the glass and this abso-rptively modulated beam is directed back. to the multiplier.
  • Thisdeposition. or absorption leaves the glass with anegative charge pattern on. one side corresponding to the positive charge pattern on the These charges neutralize each other is .lessthan the scanning time of a frame of the picture. transmission.
  • the energizing leads for the deflecting coils were brought out through the inner surfaceof the insulating support for the coils and hence were positioned immediately adjacent the scansion tube itself and this contributed to the coupling between the tube elements and the deflecting coils. Since the current passing through the" deflecting coils is comparatively high in value, the coupling between the coils and the tube elements is sufficient to definitely contribute to distortion.
  • the energizing leads, which supply energy to the deflecting coils are very short and are shielded over practically their entire length. It is-another-of the objects of this invention to provide an apparatus in which this is d-one'efiicien ly and in which the aforementioned efiects are minimized.
  • This invention in general contemplates the provision of a cylindrical focussing coil form comprising a hollow insulating cylinder. Between thecylinder and the focussing coils is a special form of electrostatic shield arrangement which will be explained more fully hereinafter.
  • the main focussing coils are placed about the cylinder and supported thereby and arebroken into three sections mutually separated by insulating rings.
  • the section usually referred to as the image section of the tube two of the sections of the coil are also mutually separated bya mu-metal ring. Energizing of the coilsections is done independently and separately of each other.
  • Wrapped about the upper surface of the coils and spacer rings is, first, a fish-paper Wrapping followed by several layers of audio wire strips wound about the coil form and spaced apart by Waxed lacing twine. Each layer is covered by a wrapping of empire cloth and the entire assembly is wrapped with a winding of acetate cloth electrical tape wrap. Energizing leads are brought out through the various layers and through the top of the assembly to-the outside.
  • the deflecting coils are supported by an insulating Bakelite hollow cylinder whose outer diameter is less than the inner diameter of the insulating hollow cylinder support for the focussing coils.
  • the form ends in two ring-like metallic members at one end of the coils and a similar pair of members at the extreme end of the form.
  • a special form of shield is wound about the form and the edges thereof are held between the rings. Ove r the shield is wrapped a layer of fish-paper.
  • One set of deflecting coils is positioned adjacent this shield and over this set of coils is wrapped a layer of fish-paper wrapping.
  • a second shield member similar to the first and clamped between the metallic rings at the end of the form. Over this second shield is wrapped a layer of fish-paper wrapping.
  • the second set of deflecting coils which are placed at right angles to the first set of coils, are positioned about this upper layer of fish-paper and on top of the second set of coils is wrapped a single layer of fish-paper covered by a wrapping of acetate cloth electrical tape wrap. Both sets of coils are separated from the metallic clamp rings by an insulating ring spacer.
  • a third metallic member comprising a hollow re-entrant cylinder flanged at one end is provided, and fastened to it is an insulating strip. Energizing leads for the deflecting coils are brought out through openings bored lengthwise through the solid part of the cylinder wall to terminals on the insulating strip and thus are not only short but are shielded from the focussing coils and particularly from the tube itself.
  • the deflecting coils are brought out through openings bored lengthwise through the solid part of the cylinder wall to terminals on the insulating strip and thus are not only short but are shielded from the focussing coils and particularly from the tube itself.
  • the flanged part of the re-entrant cylinder abuts against the outer surface of an end plate at one end of the focussing coil form, when the deflecting coils as a unit are slipped into the hollow section of the insulating cylinder supporting the focussing coils. This further improves the effective grounding of the electrostatic shields through a low impedance path.
  • the so-called re-entrant cylinder above mentioned forms a space between its outer wall and the insulating cylinder which acts as a support for the deflecting structure and this space is used to hold an alignment coil.
  • the coil is contained in the space between two cylindrical copper sections and then the edges thereof are connected by a copper strip, this forming an arrangement that resembles a thick copper ring.
  • Fastened to the copper ring is an aluminum backing ring, and between the aluminum and the copper there is placed a brass ring,the outer periphery of which is cut with gear teeth.
  • the hand-operated gear wheels which have been referred to all are mounted in a rack-like member having one portion thereof containing a ring into which there is fitted the neckof the tube with which this apparatus is used.
  • the rack fastens to an end plate at the end of the'focussing coils and the gears mesh with the gear rings on the various parts of the apparatus that have been referred to hereinbefore. This will be clearly seen from inspection of the drawings. While the focussing coil itself remains stationary, the deflecting coils can be moved relatively to the focussing coils and the tube, and the alignment coil can do likewise. Means also are provided for moving the tube relatively to either the deflecting cells, the focussing coil or the alignment coil.
  • a cylindrical memtwo is wound an additional focussing coil which is used with the image orthicon, and the size of the cylinder is such that it may be slipped into and held by the focussing coil assembly, and the end of the unit remote from the flange-like ring abuts against and is fastened securely to the front end plate on the deflecting coil when the cylinder is slipped into the focussing coil assembly.
  • a further cylindrical member which terminates in a flange-like ring is provided and this member is comprised of insulating material.
  • a vacuum tube socket At the inner end of the cylinder there is fastened a vacuum tube socket to accommodate the upper terminals of the scansion tube, that is the terminals brought out from the body of the tube. Copper strips are led along the inner surface of this cylinder and brought out and connected to terminals on the face of the flange-like or ringlike end of the cylinder and energizing potentials may be furnished to the scansion tube through these terminals, the copper strips being connected at their other end to the tube socket.
  • the cylinder itself is adapted to be slid into the cylinder holding the additional focussing coil until the flange-like end of each of these cylinders abuts each other.
  • a mu-metal ring On either side of the tube socket there is positioned a mu-metal ring to act as an electromagnetic shield member.
  • a mu-metal or A metal ring is fastened at the end of the additional focussing coil so as to lie between the focussing coil and the deflecting coil assembly 7 and is positioned so as to be substantially in the -herholdingthe. hand. operated gears. .of the-.tube. seatsin thetube socket .whichjhas .beerr referredtobefore and .the pins. comingout oixthe'.
  • the tube neck is passed through .the openingin the insulatingcylinder :mentioned immediately hereinbef ore and. passed along throughthe focussingand 'deflectingncoil .and alignment .coil assemblies and thencezthrough .a,.supporting. collar. contained in -.a. bracket. mem-
  • the body tials may be furnished thereto.
  • .Eig.;.1 is a partial ecross-sectional ;view;.of ..,a
  • FIG. 1 is a partial cross-sectional viewof .one send portion of Fig. 1;
  • FIG. 3 isan exploded perspective-showing the .entire arrangement in accordance :with this invention
  • Fig.- 4 is a perspective view of-another end-of the..arrangement. in accordance with this inven- ;.tion .and showing supporting apparatus-tor the -;cathode ray tube usedwiththe apparatusand alsodriving "apparatus. for adjusting portions. of
  • FIG. 5 is a partial showing of one of the shieldv,i'ng means utilized in the inventiomand ;
  • Figs. 6 and 7. are schematic showings of the ad- .ditional focusing. coil and-the mount therefor.
  • iport is a short metal cylinder ll having the, end
  • Contiguous with each of thecylinders II is a flange-like metallic member 12 whichjis partially counter-sunk so that the upper edge of the flange M will fit into the counter-sunk portion' of the flange 12 but may beslightly separated apart from the bottom ofthe. counter-sunk por- 'tion and which, "with" flang -12, forms a clamp.
  • shield memberl-3 Positioned about the outer surface of shield memberl-3 is a layer of empire cloth and-next are the focussi-ng'coils which, in this particular invention, comprises four diiierent sectionsof coils-three of which are contained betweenthe .two flange or ring members l2.
  • Thethreesections of the focussing coil contained between the flanges I2 are l5, I6, and i? and they are spaced apart from eachother by Coils l5 and it are separated by two Bakelite insulating rings 58 and 59 which themselves are separated apart by a metallic ring .20 comprised of mu-metal or A metal. Coils i6 and I! are separated apart by a single insulating, ring 2
  • the coils l5 and H are spaced apart fromand maintained out of contact with ringor flange members I2 by means of Bakelite insulating rings 22 and '23 respectively.
  • V This can beaccomplished most accuratelyand most easily :bydividing the focussing coil assembly into a plurality of independent sections which may be .cIJcrgizedinsuch a fashion that focussing is ac- ;complished accurately.
  • a second wrapping 26 which comprises a double layer of empirecloth. Wound about the outer surface of the cloth 26 are a series of so-called audio steel strips 27 and these -arespacedapart by Waxed lacing twine in the ⁇ form of strip separators 28. On top of the steel strips- 21 and the separator twine 28 is wounda succession of layers which comprise a wrapping of empire cloth in a single layer'form and betweenthese wrappings are layers of audio steel strips separated by spacing lacing twine as shown.
  • a second coil form or support of Bakelite or other appropriate insulating material in the form of a hollow cylinder 40 is provided for supporting the unit which constitutes the deflection coil unit. Wound about a portion of the outer surface of the hollow cylinder 40 is a sheet of shielding material 41 which will be described more fully hereinafter in Fig. 5. Around the upper surface of the sheet is wrapped a double wrapping 42 of fish paper.
  • the horizontal deflecting coils 43 then are positioned at the end of the insulating cylinder 49 which is most closely adjacent the body of the scansion tube during operation, and by body is meant that portion of the tube which contains the target member, and also at this end is a metallic cylinder 44 which has the end thereof terminated in a ring or flange-like member 45.
  • cylinder 44 must be fastened to the insulating cylinder 49.
  • a second ring-like member 46 Positioned adjacent the ring-like member 45 is a second ring-like member 46 which has a counter-sunk section.
  • may be slotted so that it may be folded upwardly and. held between rings 45 and 46 which co-act to form a clamping member.
  • An insulating separator 41 separates the horizontal deflecting coils from the ring 46.
  • a second insulating separator ring 48 Positioned next to the ring 43 is a metallic ring 49 which is countersunk on opposing surfaces. A flanged metallic cylindrical ring 50 is positioned adjacent to and fitting into one of the countersunk portions of ring 49.
  • may be bent upwardly and held together by the rings 49 and 58 which act as a clamp to hold the shield and also to ground the shield since the ring will contact the metallic end section of the focussing coil assembly when it abuts against it.
  • the de flection coils per se may be of the type as illustrated, for instance, in U. S. Patents Nos. 2,155,514 of April 25, 1939, and 2,167,379 of July 25, 1939, both to W. A. Tolson.
  • a second special shield member 58 Over the horizontal deflection coils 43, there is wrapped a double Wrapping of fish paper 55 and about the outer surface of the fish paper is wound a second special shield member 58 which will be shown more clearly in Fig. 5. Over the shield 56 is wound a single wrapping of fish paper 51.
  • the slotted edges of the special shield 56 may be bent upwardly and one edge may be held between ring 46 and a second ring (not numbered for purposes of clarity of illustration) which co-acts therewith to act as a clamp.
  • the other edge of the shield '56 is similarly held between member 49 and a metallic ring (also not numbered for purposes of clarity)
  • Both of the unnumbered elements are separated from the vertical deflection coils 60. (only a portion of which have been illustrated) by insulating rings.
  • the upper surface of the vertical deflection coils is wrapped with a single wrapping of fish paper and a wrapping of acetate cloth electrical tape 32.
  • the relative positioning of the vertical and horizontal deflection coils is
  • a metallic element Positioned in contact with the ring-like edge and. the upper surface of the metallic ring member 59 is a metallic element which may be described as a re entrant hollow cylinder at having a flanged end or that could be described as a short metallic cylinder terminating at each end in a ring like metallic member and in which one of the members is directed downwardly into the hollow cylinder.
  • the shell of the member 55 is bored through lengthwise with several holes and an in- 10 sulating ring-like strip 55 is fastened to the outer surface of the member 55 and has a number of terminals 5? which also may be seen more clearly by reference to Figures 2 and. 4.
  • the member 65 is four-fold. Firstly, the outer ring-like end of the cylinder holds the terminal strip 65 and the energizing leads from both the horizontal and the vertical deflecting coils may be made very short and may be brought out through the holes in the shell to the terminals 61, thus shielding these leads from the focussing coil for the greatest portion of their length and also, to all intents and purposes, eliminating any interaction between the leads themselves and the internal elements of the scansion tube with which this apparatus is associated and which interaction would take place due to electrostatic coupling. Also from a mechanical viewpoint this is highly superior construction over the prior art where the leads were brought up out of the inner surface of the deflecting coil assembly and therefore permitted electrostatic cross-over between their leads and the tube elements. Insertion of the tube and withdrawal thereof from the assembly also produced a certain amount of wear on the insulation of the leads.
  • the ring-like end of the member 65 abuts against the surface of the metal end plate i2 of the focussing coils and in conjunction with members 49 and El ⁇ forms a good metallic ground for shields 42 and 55 on the outside of the coil structure as well as limiting the degree to which the coil may be inserted into the hollow cylincler I'll.
  • the outer surface of the ring or flange in the end of the element 65 which is remote from the deflecting coils supports a toothed ring section which is adapted to co-act with a hand driven gear to turn the whole deflecting assembly relatively both to the focussing coil and to the cathode ray tube with which this apparatus is associated.
  • the co-action of these and other elements for adjustment purposes may be seen more clearly hereinafter in Figures 3 and 4.
  • the shape of cylinder 65 allows the insertion therein, in the hollow section thereof, of an alignment coil 10 which is contained within the space formed between two hollow metallic cylinders H and l2 and having the end space between them closed.
  • these cylinders have been made of copper and an aluminum backing ring 13 has been provided.
  • This coil has been energized through terminals 14 fastened to insulating terminal strip 15.
  • the edge of metallic ring 16 has been toothed so that a hand operated gear, co-acting therewith, can turn the alignment coil relatively to the cathode ray tube used with this apparatus and such gearing is shown at the point 11.
  • the alignment coil can be moved relatively to either the focussing coil or the deflecting coils.
  • bracket-like member which is positioned adjacent the alignment coil and which fastens to an end plate on the end of the focussing coil.
  • this arrangement has been omitted in Fig. 1 but will be shown clearly in the exploded view of Fig. 3 and in detail in Fig. 4.
  • the electrostatic shielding between the coils and tube is necessary because high voltages are produced in the deflection coils by the large value currents necessary to drive the coils.
  • the surge voltage from the horizontal coils can produce potentials on the vertical coil sections driving curaieowsr rents of appreciable 'value through them by capacity coupling and thus cause a superposition of horizontal deflection components on"thever"- tical deflection which appears asa vertical oscillation of the deflection lines across the screen.
  • the particular form of shielding used between thedeflection coils eliminates this efi'ect.
  • a still further reason for the shielding between the'defle'ctioncoil and the tube is the fact that capacity transfer of someof the surge voltage can inducepotentials'onthe tube leads nearthe socket end of the tube; These potentials appear as superimposed ripples on the output voltage from the tube.
  • the shielding eliminates this effect.
  • a capacitive coupling ofthe surge voltage produced in the deflection coils towards the front portion of the pick-up tube can similarly produce potentials on the electrostatic elements in this tube portion which may disturb the focussing action in the image section and near the target.
  • the thoroughelectrostatic shielding between the deflection coils and this front'portion of the tube eliminates such effects; n
  • mu metal ring 84 This mu metal ring usually is coated with an insulating materialand is not grounded.
  • an insulating cylindrically shaped member 95 whose end terminates in a flange-like or ring-like insulating'ni'ember 9 I.
  • the outer diameter'of the cyIinder'SU'isS'uch-that it will fit against the inner surface of cylinder Stand may be inserted therein untilthe" member 9'! abuts against the ring 8
  • Openings are provided in the tube socket into which the pin members onthe'botto'in of the body of a scansion tube used with this apparatus may be in serted. These openings are fitted with a con ducting material-anda series of coppe'r'strips 93 are provided to act asconductors between these openings and sources of energizing potential exterior to the tube.
  • the copper strips come'out of the front of the cylinder and are bent upwardly where the fasten on the front of the ring 9
  • Positioned' a'gainst the tube socket and on the side thereof into which thetube seats is a mu-metal ring 95f;
  • Fig. 2 there is shown in partial cross-section a view of" the end of the focussing coil and deflecting coilarrangement at the end thereof which accommodates the alignment coil.
  • the end plate lilll of the fecussing coil is shown with the end ring ofthe cylinder 65 of the defleeting coils being shown as abutted thereagainst.
  • the terminal strip 66 through which energized potentials are fed to the deflecting coils, isshown fastened to the ring member on the end of cylinder 65 and the terminals 6'! are indicated showing the ease with which energizing potentials can be fed to'the deflecting coil.
  • the insulating cylinderflfi, about which the deflecting coils are wound, isshown partially in cross-section and the relative positioning of the horizontal deflection cells 43; with respectto the vertical deflection coil 66- is indicated. Terminals I05 through which the alignment coil maybe energized are shown.
  • FIG. 3 there is shown an exploded Viewdn perspective of the entire apparatus to show the relative positioning of the various parts whieh have been described hereinbefore with respect to Figure 1,- as well as the relative shapes of these parts.
  • This 'view is for purposes of principles only and no attempthas been made to maintain actual scale relations since the relative size of the elements will depend upon the particular tube with which the apparatus may be used.
  • the'outside wrapping 30 of the focuss'in'g coil is shown and the coil is illustrated asbeing" contained between two aluminors end plates HQ and- Hi.
  • the cylinder 89 having the ring-like members BI and 32 is illustrated with' the additional focussing coil 83 containe'd therebetween.
  • the cylinder will be inserted in the opening furnished by the cylinder on which the focussing coil assembly between two end-plates llllan'd Ill-is wound.
  • the cylinder 8Q w'ill beihserted' into the opening until the ring 82 abuts against the end plate H0.
  • a bracket member having sides H5 and H6 and a front plate In.
  • the bracket may be fastened to the end plate I I I by means of screws or bolts.
  • a ring-like collar H8 which may be seen more clearly with reference to Figure 4.
  • a screw member' is provided for holding the tube neck firmly against the collar.
  • the collar a geared segment H9 which may be turned by hand-operated gear I for turning the tube through a small arc.
  • the gear wheel I2I is provided for engagement with the geared segment on the alignment coil and gear wheel I22 may be engaged with the geared segment on the focussing coil. Adjustments of these structures may be made by means of these hand-operated gears.
  • Fig. 4 there is shown, partially broken away, the bracket comprising members H5, H6 and II! along with the collar H8, the latter having an interior in which is seated a cushioning ring I25 of spring bronze.
  • the en-- gagement between gear I22 and gear segment 80 on the deflecting coils is shown as well as the engagement between gear I2I and the gear segment as illustrated at TI on the alignment coil.
  • the relative positioning of the alignment coil with respect to the deflecting coils and the end plate III is shown and the fact that the alignment coil physically goes up partially into the deflecting coil unit is brought out and the position will be such that its correct electrical relationship with the focussing coil is maintained.
  • FIG. 5 there is illustrated one of the sheets which form the electrostatic shields which have been referred to hereinbefore in this specification and which have been illustrated as elements I 3, 4
  • the shield has consisted of a so-called kraft paper insulating sheet 530 on both sides of which there is a layer of a conducting material, which, in actual practice, hasbeen a sheet of tin foil.
  • a conducting material which, in actual practice, hasbeen a sheet of tin foil.
  • the solid lines indicate the conducting material on one side of the sheet and the dotted lines indicate the configuration of the conducting material on the other side of the sheet, after it has been cut in accordance with the present invention.
  • the method of preparing the shield has been as follows:
  • these rings or annular members are to keep the fringe flu'x emanating from the ends of the deflecting coils from affecting the electron multiplier section of the scansion tube with which this apparatus is associated. This is done by providing a low reluctance return path for the flux through the two ringsof magnetic material and through either the audio steel strips or the iron sheath around the apparatus and thence back through mu metal rings 28 and 84 to the deflecting coils themselves. In actual practice, this has resulted in considerable improvement in the results obtainable with the apparatus.
  • the structure may be formed of a cylindrical metallic member which has at one end thereof a flange-like annular member and at a position intermediate the other end thereof asecond annular ring embracing the outer periphery of the cylinder.
  • the additional fo'cussing coil is wound in the space between these two annular members.
  • the surface of the cylinder is cut away beginning at a positionin the neighborhood of the annular member 82 so as to form two windows through the surface of the cylinder and these windows continue to a position near the end of the cylinder.
  • the surface of the cylinder is cut away so that two relatively narrow conducting strips, one of which is shown asthe strip I50, extend from the neighborhood of the annular ring 82 to a position near the end cf the cylinder and this leaves the end in the form of a ring of conductin material il.
  • the annular ring 85 of Fig. 1 is provided against which the mu metal ring 84 of that figure rests.
  • the windows in the surface of the cylinder 80 then maybe filled by an insulating material such as Bakelite or other well known materials so as to give rigidity to the structure.
  • Fig. '7 there is shown an alternative form of the additional focussing coil support and one which has been very effective in practice. In some respects this may be described as a modification of the arrangement shown in Fig. 6.
  • the sections, which in Fig. 6 are the window sections comprise, in this arrangement, a series of conducting strips which are cut from the surface of the cylinder itself and these conducting strips are shown, for ex-' ample, by the strips I55, I56 and so forth.
  • This structure provides, however, a good ground connection from the outer frame of the apparatus, as for instance the members H0 and III, to clamping members 45 and 46 which clamp on of the electrostatic shields and the unnumbered clamping member cooperating with the member 46 and clamping the other electrostatic shield.
  • An electron beam controlling apparatus comprising means for focussing the electron beam, means for deflecting the electron beam, and at least one electrostatic shield interposed between said fccussing means and said deflecting means comprising a conducting material with a plurality of sets of strips of conducting material, each set having an individual conducting member connected thereto for electrically connecting together the strips forming each set.
  • An apparatus for influencing a cathode ray beam comprising means for focussing said beam, means for deflecting said beam, and at least one electrostatic shield member interposed between said focussing means and said deflecting means, the electrostatic shield member comprising a sheet of insulating material having positioned on either side thereof a sheet of conducting material, the conducting material of each sheet having portions of the conductor removed so as to form a plurality of sets of individual strip-like members each spaced apart from the other strips of the same set and of other sets and having a free end of each strip positioned adjacent a free end of the strips forming another set, at least a por tion of said strips being mutually electrically connected.
  • Apparatus for influencing a cathode ray beam formed within a cathode ray tube comprising an insulating substantially tubular shaped supporting member for accommodating the tube in which said cathode ray beam is formed, means for deflecting the beam in at least one coordinate of movement, means for focussing the beam, said latter means at least partially embracing the deflecting means, electrostatic shielding means positioned between the focussing means and the deflecting means, and electromagnetic means interposed between the deflecting means and the position of the target of the cathode ray tube When in operative position.
  • Apparatus in accordance with claim 5 wherein the means for focussing the cathode ray beam comprise a plurality of individual coils which can be separately excited.
  • Apparatus for influencing the electron beam formed within a cathode ray tube which has a neck section within which the cathode ray beam is formed and a body section containing a target area comprising a first tubular shaped insulating support by which the neck section of the cathode ray tube may be at least partially embraced, deflecting means supported by said tubular member, a second tubular shaped insulating member having a diameter larger than that of the first tubular member and which is adapted to embrace at least a portion of the first tubular member, means for focussing the cathode ray beam supported by a said second tubular member and comprising a plurality of individual electromagnetic coils, an electromagnetic ring at least partially embracing the second tubular member and positioned between two of the individual focussing coils, a second electromagnetic ring at least partially embracing the first tubular means and positioned between the deflecting means and the body of the cathode ray tube at its operating position, and electrostatic shield means positioned
  • Means for influencing the cathode ray beam formed within a cathode ray tube having a neck section in which the cathode ray beam is formed and a body section containing a target area comprising a first tubular insulating support, deflecting means positioned about and supported by said tubular means for deflecting the cathode ray beam in at least one coordinate, a second tubular insulating support means having a diameter larger than that of the first insulating support means and into which said first tubular means may be positioned so as to have at least a part thereof embraced by said second tubular means, means supported by said second tubular means for focussing the cathode ray beam, electrostatic shield means interposed between the focussing means and the deflecting means, a third tubular shaped member, a tube socket means contained within said third tubular shaped member, the diameter of the third member being such that it may be positioned within the first and second tubular shaped members so that at least a portion thereof is embraced thereby,
  • a laminated combination electrostatic and electromagnetic shield comprising a sheet of insulating material having a sheet of conducting material positioned on each opposite side surface thereof and wherein each of the sheets of conducting material is slotted to form from each sheet a plurality of individual strips of conducting material lying on each of said opposite side surfaces, adjacent strips on either given surface being separated by said slots and wherein the slots on one surface are coincident and in normal transverse alignment with the strips on the other surface.
  • a laminated combination electrostatic and electromagnetic shield comprising a sheet of insulating material having a sheet of conducting material in contact with each face thereof, said sheets of conducting material having portions thereof removed therefrom to form a surface structure on each face, each of the formed surface structures having a configuration which comprises a supporting strip of conducting material along each of two opposite edges of the sheet face and a series of spaced secondary strips emanating from the supporting strips, each of said secondary strips having a free end, each of said conducting sheets, and the configurations defined thereby, being further so proportioned and the two sheets so oriented relative to one another that slotted areas on one sheet face are transversely projectible normally thereto to fall on areas of conducting material on the other sheet face.

Landscapes

  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
US729421A 1947-02-19 1947-02-19 Electron beam control apparatus Expired - Lifetime US2490731A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US729422A US2463720A (en) 1947-02-19 1947-02-19 Electron beam influencing apparatus

Publications (1)

Publication Number Publication Date
US2490731A true US2490731A (en) 1949-12-06

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ID=24930948

Family Applications (2)

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US729422A Expired - Lifetime US2463720A (en) 1947-02-19 1947-02-19 Electron beam influencing apparatus
US729421A Expired - Lifetime US2490731A (en) 1947-02-19 1947-02-19 Electron beam control apparatus

Family Applications Before (1)

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US729422A Expired - Lifetime US2463720A (en) 1947-02-19 1947-02-19 Electron beam influencing apparatus

Country Status (6)

Country Link
US (2) US2463720A (xx)
BE (2) BE480460A (xx)
DE (1) DE967353C (xx)
FR (2) FR960167A (xx)
GB (2) GB653631A (xx)
NL (2) NL138787B (xx)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2845562A (en) * 1954-07-07 1958-07-29 Rca Corp Electromagnetic deflection yoke
US2880338A (en) * 1953-10-17 1959-03-31 Pye Ltd Television pick-up tube
US3345537A (en) * 1965-02-12 1967-10-03 Melpar Inc Photoelectric shield including a dielectric sheet sandwiched between two metal sheets
JPS4936819U (xx) * 1972-05-18 1974-04-01
JPS49125619U (xx) * 1973-02-27 1974-10-28
US4237438A (en) * 1978-12-19 1980-12-02 Rca Corporation High resistance continuous shield for reduced capacitive coupling in a deflection yoke

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL89166C (xx) * 1950-11-06
NL193774A (xx) * 1954-01-15
US2837674A (en) * 1954-11-17 1958-06-03 Rca Corp Electro-magnetic deflection apparatus
US2761989A (en) * 1955-02-28 1956-09-04 Rca Corp Cathode ray tube device
US2977501A (en) * 1956-06-14 1961-03-28 Edgerton Germeshausen & Grier Cathode-ray apparatus and method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2047159A (en) * 1935-07-17 1936-07-07 Galvin Mfg Corp Electrostatic shield
US2172733A (en) * 1935-03-29 1939-09-12 Deflection coil
US2217409A (en) * 1937-04-26 1940-10-08 Rca Corp Cathode ray control apparatus
US2234998A (en) * 1938-12-06 1941-03-18 Robert H Worrall Electrical shield
US2314409A (en) * 1940-09-28 1943-03-23 Bell Telephone Labor Inc Magnetic coil structure
US2362034A (en) * 1941-06-25 1944-11-07 William F Stahl Shield for electrical currents

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2085742A (en) * 1930-06-14 1937-07-06 Farnsworth Television Inc Electron image amplifier
US2188579A (en) * 1933-05-27 1940-01-30 Loewe Radio Inc Cathode ray tube, more particularly for television purposes
IT349671A (xx) * 1936-02-28

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2172733A (en) * 1935-03-29 1939-09-12 Deflection coil
US2047159A (en) * 1935-07-17 1936-07-07 Galvin Mfg Corp Electrostatic shield
US2217409A (en) * 1937-04-26 1940-10-08 Rca Corp Cathode ray control apparatus
US2234998A (en) * 1938-12-06 1941-03-18 Robert H Worrall Electrical shield
US2314409A (en) * 1940-09-28 1943-03-23 Bell Telephone Labor Inc Magnetic coil structure
US2362034A (en) * 1941-06-25 1944-11-07 William F Stahl Shield for electrical currents

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2880338A (en) * 1953-10-17 1959-03-31 Pye Ltd Television pick-up tube
US2845562A (en) * 1954-07-07 1958-07-29 Rca Corp Electromagnetic deflection yoke
US3345537A (en) * 1965-02-12 1967-10-03 Melpar Inc Photoelectric shield including a dielectric sheet sandwiched between two metal sheets
JPS4936819U (xx) * 1972-05-18 1974-04-01
JPS49125619U (xx) * 1973-02-27 1974-10-28
US4237438A (en) * 1978-12-19 1980-12-02 Rca Corporation High resistance continuous shield for reduced capacitive coupling in a deflection yoke

Also Published As

Publication number Publication date
NL138787B (nl)
BE480411A (xx)
GB666854A (en) 1952-02-20
FR960167A (xx) 1950-04-14
DE967353C (de) 1957-11-07
GB653631A (en) 1951-05-23
FR960166A (xx) 1950-04-14
BE480460A (xx)
US2463720A (en) 1949-03-08
NL80751C (xx)

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