US2207841A - Electric discharge device - Google Patents

Description

Filed Nov. 25, 1932 FIG.

INVENTOR H. m WE/NHARI 61/ 0mm 6. Maud A TTORNE V Patented July 16, 1940 ELECTRIC DISCHARGE DEVICE Howard W. Weinhart, Elizabeth, N. J., assignor to I Bell Telephone Laboratories, Incorporated, New

York, N. Y., a corporation of New York 7 I Application November 25, 1932, Serial'No. 644,221" to Y 20 Claims. (Cl. 250161) UNITED STATES PATENT. OFFICE a This invention W111 behereinafter described vessel A p ral y of deflectin pl s are sup- "6 in connection with the type of electric discharge ported on one end of the glass column to alter device known in the art as the Braun tube which the path of the cathode beam as it leaves the 1S used rimaril for the measurement or the mglass ol mn h d v ce i h h y va u d n dication of electric power, the wave form of alterorder to operate at high voltages The internal 1 nating current or potential or similar conditions magnetic winding tends to concentrate the beam 10 w in electrical circuits. of cathode rays and prevents the accumulation of One of the diificulties of this type of device is electric charges on the glass wall of the device its relatively short life due to the filamentary A feature of the invention relates to the con cathode burning out after a relatively short pecentration of the beam of rays as close as possi- I riod When a gas used in the device for the ble to the axis of the vessel In order to accom- 16 purpose of focussing or providing a conducting plish this result the magnetic focussing CO1). s medium for the cathode beam, positive ions are supported in immediate proximity to the axis of produced in the space discharge between the the vessel and the cathode ray beam passing cathode and anode causing deterioration of the through the coil is continually within the focuss- 2o cathode coating and tending to reduce the opeiing field of the coil in its passage from the anode 20 ating life of the device. Furthermore, the use of to the deflecting plates.

a gas as a focus sing aid limits the potentials Another feature of the invention relates to a which may be applied to the electrodes unitary support which maintains the elements Another difiiculty generally experienced with of the cathode ray tube in alignment in the dethis type of device is the low actinic value of the vice ThlS support consists of a cylindrical pencil or beam of cathode rays pro ected toward mount or column having a chamber enclosing the the screen of the device. The low actinic value cathode, a bobbin portion supporting the magof the pencil of rays is due to a'normal dlfillSlOn netizing coil and a flared por ion Supporting the of the pencil of rays in the device In order to deflecting plates. This mount is supported solely to take advantage of the low intensity of 11ht profrom the stem of the vesseland provides an asduced in the device it has been necessary to ensembly which may be constructed as a unit beclose the device in a dark chamber or perform fore incorporating it in the device. the measuring operations in a dark room A further feature of this invention is: that the An obJect of this invention is to concentrate mount is constructed to form retaining and anthe beam of cathode rays in an electric discharge choring means for the magnetizing coil so that 5 device so that the pattern of the wave promoted the leading-1n wires sealed in the vessel are ieon the screen of the device may be readily oblievecl from strains served in daylight. This can only be accom- These and other features of the invention-will plished when the beam of cathode rays is con be more clearly understood from the following centrated to a high degree. I detailed description taken in connection with the In accordance with this invention, the beam of accompanying drawing. cathode rays emanating from the cathode is fog. l is an enlarged perspective view of a cussed on the screen by an internal magnetic cathode ray tube made in accordance with this winding which prevents dispersion of the pencil invention with a portion of the enclosing Vessel of cathode rays passing through the vessel to broken away to show the internal assembly of 45 the screen In a preferred embodiment of the the electrodes; I invention the electric discharge device comprises Fig. 2 is a diagrammatic showing of a portion an enclosing vessel having a coating deposited of the enclosing vessel illustrating a modification on one end which is capable of becoming fluoof the vessel to provide a fiat end portion In rescent when a cathode ray beam is directed tothis figure the modified glass portion is super- 50 ward it, and arranging the electrodes at the posed on a configuration of the vessel as disother end of the vessel in a vertical line along closed in Fig 1 to indicate the proportions of the the axis of the vessel. The electrodes are supdifferent forms; v ported on a glass superstructure extending Ii cm Fi 3 is n enl r tail Vi w in rossu' the stem which includesa hollow glass vessel tion of the electrode assembly shown in the lower portionof Fig. 1 illustrating the support of the cathode and anode in relation to the glass column and the support of the column from 1he glass stem;

Fig. 4 is an enlarged view, partly in cross-section of the portion of the glass column supporting the magnetizing coil; and

Fig. 5 is a diagrammatic view showing the relationship of the deflecting plates and the position of the supports of the plates extending from the glass column in Fig. 1.

Referring to the drawing, the electric discharge I device of this invention comprises an enclosing vessel having an elongated cylindrical portion l0, an extending conical portion H and a. concave end portion l2, the end portion 12 serving as a depository surface for an internal coating of material l3, such as zinc silicate and calcium tungstate. This material, which forms a screen in the device, becomes fluorescent when a cathode ray beam is directed toward the material and is capable of showing the trace or form of an electric wave so that the wave may be viewed visually or photographic reproduction made of the wave form traced on the screen. The fluorescent screen may also be deposited on 'a flat surface as shown in the modification of Fig. 2 in which the conical portion H of the vessel is changed to a cylindrical portion M and a glass disc l5 having a diameter the same as the internal diameter of the cylindrical portion I4 is fused to the cylindrical portion to provide a tight sealed joint.

The enclosing vessel is provided with an inwardly projecting stem l6 which is fused to the elongated cylindrical portion In and forms a seal for the leading-in wiresoi the electrodes and a support for the electrodes. The stem I6 is provided with a central integral projection 11 which terminates in a tubular hollow portion l8 open at its free end. 7 forms a chamber for a helical ribbon cathode IQ of the oxide coated type which is maintained project from opposite sides of the chamber l8 and are sealed in the glass portion of the stem it. Although a filamentary form of cathode is shown in the device of this invention, it is, of course, understood that any indirectly heated cathode may be substituted for the fllamentary cathode. The chamber formed by the tubular glass portion i8 is substantially closed at one end by an apertured metallic focussing disc 23 which is sealed into the edge of the glass tubular portion is and permits emanation of electrons from the cathode through the aper- A leading-in wire 25 attached to the disc 23 extends through the bead 20 and is sealed in the stem IE to apply a suitable potential to the focussing disc.

A unitary mount or column is supported from the glass stem and consists of a bell-shaped portion 23, which forms a chamber around the cathode assembly and segregates the leading-in wires for the cathode and disc, an elongated tubular bobbin portion 21, shown more clearly in Fig. 4, and an outwardly flared termination 28. The mount is provided with spaced annular blown portions 29 and 30 intermediate the bellshaped portion 26 and the flared termination 28. It will be evident from the disclosure that the bobbin portion 21 and the flared termination 28 provide a central tubular chamber for the passage of the cathode ray beam. The unitary mount may be supported solely from the stem l6, for instance, by glass arms 3| and 32 which are fused to the bell-shaped portion 26 and the stem It. A tubular metallic anode 33 is supported in a solid glass portion 34 intermediate the bell-shaped portion 26 and the bobbin portion 21 of the mount and forms a communicating passageway for the cathode beam between the tubular chamber of the mount and the aperture 24 in the focussing disc 23. A leadingin wire 35 is attached to the tubular anode 33 and extends exterior to the bell-shaped portion 25 and is sealed in the glass stem l6 at 36. The

portion of the leading-in wire extending between the anode and the seal is surrounded by a glass tubular member 31.

The emanation of electrons from the heated cathode and the projection of the electrons through the primary focussing disc 24 serve to produce an electron stream or cathode ray beam which is pro ected through the tubular anode 33. After leaving the anode the beam normally has a tendency to sprea'd'out or disperse and consequently reduces the intensity of the beam which is desired'to be projected tothe screen on the end'of the vessel. In accordance with this invention the cathode beam after leaving the anode is focussed'magneti c ally and concentrated in immediate proximity to the axis of the yes-- sel to insure a pencil of light of high intensity and high actinic valueso that the trace of the beam on the screen maybe observed in daylight without the aid of a dark chamber surrounding the device. This is accomplished by placing an electromagnet winding 38 around the glass'column or mount and entirely. within the enclosing vessel of the device.

The electromagnet winding consists of a hum-Q 1 ber of layers of preglowed copper wire and the turns thereof are coated with vacuum-treated insulation, such as lacquer .or fused aluminum oxide, commercially known as Alundum ce-. ment. The winding is placed on the bobbin portion of the mount and the spaced blown portions 29 and 30 maintain the winding inposi tion. An anchor wire 39 is fused into the blown portion 29 and attached to one end of the windihg adjacent the coil, to relieve strain on the termination of the winding which projects out to a terminal 40 fastened to a projection Mon the vessel ill, the termination of the winding being attached to a suitable. leading-in wire sealed in the end of the projection 4|. A similar anchor wire 42 is fused in the blown portion 30 of themount in a position from the position of the anchor wire 39 in the portion 29. The anchor wire 32 is attached to the other termination of the winding 38 to relieve strains on the leading-in wire extending to extension 63 and the extension is provided with a terminal cap-M to which the end of the winding is soldered. This arrangement places the ex ternal connections of the electromagnet coil at diametrically opposite points on the exterior of the vessel and they are arranged in alignment with the terminations of the winding. as. they. leave the bobbin portion of the mount. 7

When current flowsthroughthe magnetizing winding 38 an intensive magnetic field surrounds. the axis of thevessel withinthe tubular cham-" ber formedby the mount, The, cathode beam projected from .the. tubular :anode 33 is focussed by this magnetic field-to insure-a beamofhigh intensity andzhigh.actinic'eificiency.

ean, 3

aeozsgi i 3 The control of the cathode ray beam after flecting'plates for acting on said beam, an elonleaving the magnetic focussing field is accomgated tubular member surrounding said cathode fplished by a plurality of deflector plates which and anode and through which said beam is diare arranged adjacent the exit of the tubular rected, and magnetic focussing means supported mount in'the device. These plates are arranged by said member, said member also supporting 5 1, a deflector plate 45 is arranged parallel to ray beamtoward said screen along the axis of said 46' which isfused into the rim of the flared magnetic focussing means between said plates 41 is arranged parallel to plate 45 and supported sel supporting said anode, magnetic means and from the flared portion 28 byan upright wire plates coaxially with respect to said cathode and 48. A tubular projection 49 extends from the screen. I I 5 portion IU of the enclosing vessel and is pro- 4. An electric discharge device comprising a vided with a terminal cap 50 which is inalignvessel having a fluorescent screen at one end, a

e terminal cap 58 and the plate 45 are contowards said screen, a cylindrical mount supa similar projection 52 which carries a terminal of said mount, and a plurality of deflecting plates cap'53 attached to a leading-in wire 54 consupported on the other end of said mount.

the planes of the deflector plates 45 and 41. ported in said vessel adjacent said cathode, a The plates 55 and 51 are supported from the tubular anode supported by said mount at one flared portion 28 of 'themount by supporting end, a plurality of deflecting plates supported by wires 56 and 58, respectively. said mount at the other end, a magnet wind- It will be noted 'from Fig. 5 that the plates ingosurrounding said mount, and confining means supports 46 and 48 of deflector plates 45 and 47 6. An electric discharge device comprising a which, extends from the center of the plate 55 at one end, a plurality of deflecting plates supbeam in its passage to the fluorescent screen'on a p a y 0 d fl n P a es Supported by said v described and illustrated in a particular embodi- 8; electric discharge device comprising a only to be limited within the scope of the apmount having a separate hollow portion sur 0 anode, electromagnetic means and plates with a d S m adapted to project a cathode ray beam 7 respect to said cathode and screen. toward said screen, a cylindrical mount in said 2 An electric discharge device comprising a Vessel, a tubular anode within said mount, a.

forming the sole support for saidmount from terminations of said winding,leading-in wires for said stem. said plates sealed in said vessel in direct line with {110; An electric discharge device comprising an the center of each of said-plates, and a fluorescent enclosing vessel having a fluorescent screen at screen on the end of saidvessel adapted to indione end, a cathode at the other end adapted to cate the trace i said cathode ray beam.

project a cathode ray beam toward said screen, a 15. A cathode ray tube Comprising a enclosing cylindrical mount supported in said vessel vessel, a cathode adapted to emit a stream of axial with said cathode, a tubular anode within electrons supported in said vessel at one end said mount, a magnet winding on the exterior thereof, a fluorescent screen at the opposite end it) surface of said mount, a plurality of deflecting of said vessel, an accelerating anode between said lo plates disposed on one end of said mount, and screen and said cathode and positioned to impart leading-in wires sealed in said vessel in direct line when energized the final acceleration tosaid with the center of each of said deflecting plates. Stream Of electrons, thereby enabling Saidm, 11. An electric discharge device comprising an to impact said screen, and an electromagnetic coil enclosing vessel having a stem at one end, a fluo- Supported- Within Said Vessel and locatedto 5111- l rescent screen at the other end, a member formround said stream of electrons after it has been ing a plurality of contiguous hollow chambers finally accelerated by said anode. supported from said stem, a tubular anode posi- 16. A cathode ray tub Comprising an enclosing tioned between said chambers, a cathode supvessel, a cathode adapted to em't a stream of ported within said chamber adjacent said stem, a el ct ons pp ed in sa vesse a fluorescent 2 plurality of deflecting plates supported from the Screen a the PP end 0f Said Vessel, an anode other end of said member, and a magnetic coil between said screen a 6. said cathode and having supported by said member intermediate said ana beam Canal therein Sharp d 110 finally define h ode and deflecting lates, cross-sectional shape of said stream, and an elecas 12. An electric discharge device comprising an t mag t coil upp rt d W th n sa d v ss l and enclosing vessel having a, stem at one end, a, fiuolocated to SllIlOllIld said stream after said stream rescent screen at the other end, a cathode suphas b en na ly defin d. ported from said stem and adapted to be heated A Cathode-ray tube Comprising an on to emit a stream of electrons toward said screen, Source, at iiOntrOl electrode, an anode, deflecting a tubular anode adjacent said cathode through pl es, me ns for rigidly securing said electron so which said stream is projected, a plurality of des u control electrode, n d and plat s to-' flecting plates parallel to the axis of said vessel, fi in pa insulated relation, an ua ed and an internal magnetizing winding extending ve sel for enclosing and supp r in Said elements, subtantially the distance between said plates and a Stem extending into Said Vessel, means for anode and surrounding a path therebetween for porting sa d l tr n s u n sa d st m, holl w a5 focussing said cathode stream toward said screen. arms p jecting radially from an intermediate 13. A cathode ray tube comprising an enclosing portion of said vessel adjacent said plates, and a vessel having a stem terminating in a tubular por- Conductor extending m ach plate through an' tion, a cathode supported in said tubular portion, jac t arm- I 40 a perforated disc on one end or said tubular por ,A h d a t mpr s n va u- 40 tion, a refractory hollow column supported from ated vessel, a m extending h 'm a unitary said stem, said column having a bell-shaped porstructure supp On Said Stem Comprising n tion surrounding said tubular stem portion, an electron emitter, a control electrode, an acceleranode supported by said column adjacent said ating anode and sets of deflector plates, arms prodisc, a magnetic coil supported by the major por- .i rom a portion of said vessel adjacent said 45 tion of said column, a plurality of deflecting plates, and conductors extending from said plates plates extending from one end of said column, and hr ll h said a ms. a

a fluorescent screen located on the end or" said Acathodeday b Comprising a ectron vessel opposite said stem. source, a control electrode, an anode, deflecting 14. A cathode ray tube comprising an evacuplates, means for rigidly securing said electron 50. ated vessel having a stem, an integral extension s ur ntr l l tr d anode a p a s t on said stem forming a hollow portion, an elecgether in spaced insulated relation, an evacu tron emitting cathode supported in said hollow ated vessel for enclosing and supporting said eleportion adapted to emit a cathode ray beam, an merits, a stem extending into said vessel,- means apertured metallic disc closing said hollow porfor supporting said electron source on said stem, 55

tion, an elongated refractory column having a, hollow arms projecting radially from an interbell-shaped portion, a bobbin portion and a mediate portion of said vessel adjacent said flared termination, said bell-shaped portion surplates, a terminal'cap on the end of each arm, and rounding said hollow stem portion, a magnet a flexible conductor extending from each'plate winding on said bobbin portion, a tubular anode, thro gh an a j e arm to t e a sociated te'r said anode being sealed in an intermediate porminal cap.

tion of said column between said bobbin and bell- 20. A cathode-ray tube p s ng an evacushaped portions, a plurality of deflecting plates ated vessel, a stem extending th y unitary supported from said flared termination, supportstructure supported on said stem comprising an 5 ing arms joining said column to said stem, leadelectron emitter, a control electrode, an accelering-in wires for said cathode and disc extending ating anode and sets of deflecting plates, arms between said stem extension and said bell-shaped projecting from a portion of saidvessel adjacent portion, aleading-in wire for said anode extendsaid plates, and flex'ble conductors extending ing from said stem to said anode exterior of said from said plates through said arms. T

bell-shaped portion, leading-in wires for said 70' magnet winding sealed in said vessel adjacent the 7 HOWARD W. WEINHART. a

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