US2200745A - Electron discharge device - Google Patents

Description

May 14, 1940. 0. HEYMANN 2,200,745

ELECTRON DISCHARGE DEVICE Filed Oct. 15. 1957 INVENTOR OTTO HE YMANN ATTORNEY Patented May 14, 1940 2,200,745 ELECTRON DISCHARGE DEVICE Otto Heymann, Berliinsiemenssta'dt, Germany,

l assi'gnor to Siemens Apparate und Maschinen Y Gesellschaft mit beschrankter Haftung, Berlin,

a Germany, a corporation of Germany Application October is, 1937, Serial No 169 .0 90

In Germany July 8 ,"1 936 Claims. (01. 250-458) This invention relates to electron discharge devices and more particularly to cathode ray tubes having an improved electrode system.

For Certain purposes, in particular for measurements of short time periods it is known to cause the luminous spot in a cathode ray tube to perform a circular path through suitable deflection of the electron ray, whereby additional, radially directed deflection of the fluorescent spot so that upon application of suitable potentials to the paris of deflecting plates, the combined actions of the fields produce a circular trace upon the screen. 1

For this deflection magnetic fields alsomay be employed. In the simplest way a rotary field is used for this deflection. In this case the two electrode pairs 5 and B have voltages applied that are displaced in phase by 90. When employing a rotating field the electron ray describes during 5 one cycle the same envelope of a circular cone. Accordingly, at symmetrical arrangement and construction of the fluorescent screen 23 the traced spot of the electron ray 3 moves along 10 is superposed for instance for reproducing ina circular line. After passing through the ro- 10 dication marks. In this case, aside from the tating field which affects the rotation of the ordinary deflection system which may consist for cathode ray, the latter passes through the aninstance of two plates or coil pairs, an additional nular space between two coaxial cone-shaped or deflection system for the radially directed decylindrical electrodes la and lbto which the flection of the electron ray is employed. The voltage impulses are applied which cause the ra- 15 latter suitably comprises concentric surfaces of dial deflection of the electron ray. The inner derevolution electrodes such as two conical or frusflection electrode la is mounted at a conical tro-conioal electrodes coaxially disposed with drawn-in part 8 of the wall 4 of the fluorescent respect to the axis of the ray path, or cylindrical screen. The entire supporting arrangement is 20. electrodes concentrically disposed with respect situated within the cone-shaped envelope de- 2 to this ray axis, and arranged within the cathode scribed by the rotating electron ray and hence ray tube. The electron ray performing through is in the shadow of the beam. The outer elecits fluorescent spot on the screen of the tube a trode lb as well as the connection at H can be circular path passes through the annular space mounted in the hitherto customary manner, since between the two electrodes. In the hitherto the mounting arrangement of this electrode like- 25 known arrangements of such a cathode ray tube Wise lies in the shadow. The connection I2 of it is found to be a disadvantage that the mountthe inner deflection electrode la is provided suiting arrangement and connection lead for the ably across the connection line 9 preferably inner electrode of the additional deflection syspassed through the drawn-in part. In this way tem cause shadow spots on the fluorescent screen the formation of shadow parts due to the lead-in 30 of the tube thus interrupting the luminous image is likewise avoided. of the circular path. In accordance with the in- Alternatively, the electrode la may be supvention this drawback is eliminated in that the ported by stiff wire support members sealed into inner electrode of the additional deflection systhe end wall 4 of the tube envelope 2, which tem is mounted on the wall of the screen of the construction may be preferred to reduce the dif- 5 tube within the circular track passed by the ficulties encountered inglass blowing of the first luminous spot. described form of invention. Where this form An example of one embodiment of the invenof supporting the inner conical electrode is used, tion is shown in the drawing. the connection to the electrode may be effected Referring to the drawing, an electron gun, by the same means described above, i. e., a lead comprising a cathode I, heated by a filament l5, wire 9, connected to the electrode 1a is sealed a concentrating electrode H, a focusing and through the end wall 4. modulating electrode l9 and anode 2|, produces Having described my invention, whatIclaim is: a beam of electrons which is projected normal 1. A cathode ray tube comprising an envelope to the cathode I toward the luminescent screen having an end wall completely closing said en- 45 23. Interposed between the electron gun and velope, means for forming a beam of electrons screen 23 are the deflecting electrode system supported from the envelope opposite to the end 5--5, G, and 1a, lb. The deflection electrodes Wall, a first electrode system for deflecting the 5--5 and 6 are positioned mutually perpendicubeam in mutually perpendicular directions, a

lar to each and in register with the electron gun concentric electrode system for radially defiect- 50 ing the beam, and means to support a part of the second electrodesystem from the end wall.

2. In a cathode ray tube having an end wall portion completely closing said tube, a radial defleeting system comprising concentric surface of revolution electrodes, and means to support the inner concentric electrode from the end wall.

3. A cathode ray tube having an end wall portion completely closing said tube, an electron gun supported from a press member opposite to the end wall portion axially aligned with a radial beam deflection system comprising two concentric conical surface electrodes, and means to support the inner concentric electrode from the end wall.

4. A cathode ray tube comprising an envelope having a tubular portion, a conical portion and an end wall closing said envelope, an electron gun mounted within the tubular portion and supported therefrom opposite to the end wall, concentric surfaces of revolution radial deflection electrodes within the conicalportion of the envelope, means to support one of the radial defiection electrodes from the center of the end wall, a luminescent screen supported on the end wall, and linear deflecting electrodes supported intermediate the electron gun and the radial deflection electrodes.

5. A cathode ray tube comprising an envelope having a press member and an end wall closing said envelope opposite the press member, a source of electrons supported from the press member, means for focusing electrons from the source into a beam adjacent to the source, two pairs of deflecting plates intermediate the end wall and the said means, each pair of plates being per pendicular to the other, and concentric radial defiecting electrodes intermediate the end wall and the said pairs of plates, one of said radial defleeting electrodes being supported from the end wall.

OTTO HEYMANN.

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