US2076633A

US2076633A - Electron tube

Info

Publication number: US2076633A
Application number: US673571A
Authority: US
Inventors: Haines Donald Graydon
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1933-05-30
Filing date: 1933-05-30
Publication date: 1937-04-13
Anticipated expiration: 1954-04-13

Description

' April 13, 1937. D, HAINES ELECTRON TUBE File d May 30, 1933 INVENTOR DONA HMNES BY ATTORNEY Patented Apr. 13, .1937

UNITED STATES- 2.676.633 ELECTRON irons Donald Graydon Haines, Bloomfield, N. a, as-

signor to Radio Qorporation of America, a cor-- notation of Delaware Application May so, 1933, Serial No. 673,571

8 Claims.

This invention relates in general to electronic tubes and more particularly relates to tubes of the cathode ray type which employ an electron beam or beams to-control the operation.

In a more specific sense, the invention is ill-- rected to particular types of anodes to use with 'tubes of the above described type.

Inconstructing the usual cathode ray type of tube there is provided a source of electrons and, where desired, a control grid or the equivalent, an anode through which the developed electrons are projected in the form of an electron pencil, suitable deflecting fields, which may be either electrostatic or electromagnetic, or a combination of both, as well as usually some form of means, such as electrostatic or electromagnetic, forv focusing, and in certain uses of the tube, for example in television; there ls'provided a screen structure which is caused to .become fluorescent I upon the bombardment of the cathode ray pencil thereupon. Many and varied uses for cathode ray tubes have already been proposed among which is its use as an oscilloscopein which it is possible to observe certain phenomenon and to visualize certain electrical wave formations. Otheruses are for both the transmission and reception of television images, and still other uses are as 'frequency multipliers.

used in other fields than those above suggested. By the present invention, one of the primary objects is to produce a tube of the cathode ray type in which it is possible to obtain variations, in theianode current flowing-through the tube .in accordance with varying displacements or deflection of the cathode ray pencil generated therein, 80 arranged the tube finds particular application for use as a frequency multiplier.

" 40 Still other objects of the present invention will 50 of the arrows.

According to the prior art, as particularly exw empllfied by patent to Van der 13111, No. 1,613,626, granted January 11, 1927, provision has been made for the use of a cathode ray tube as a 66 frequency multiplier. When so arranged the moving betweenv spaced anode elements.

Thus, in general, tubes of this type have wide application and also may be tube is constructed so as to provide a pluralityof distinct anode members certain of which are connected so as to feed the output current in one direction and certain others of which are con-' nected so as to feed the output current in an op- 5 posite direction. The present invention, however. departs somewhat from the general arrangement provided bythe Van'der Bijl construction, in that, r it is possible to obtain a continuous current in contrast to any interruptions in the current flow 10 produced during the time the electron beam is Further, the present invention providesdistinct improvements over the arrangements of the prior vart by making use of the different secondary elec- 15 tronic emission effects of different materials to maintain and produce changing strength currents flowing'in accordance with changing deflections of the electron pencil, or beam within the tube. a

If reference is now made to the drawing it will 20 be seen that the cathode i is provided as an elongated cathode which is suitably shielded by means of a shielding member 2 which provides ways and means by which the generated electrons are caused to flow toward the various anode members, to be later described. Between cathode l and anode 4 there is provided what has been generally designated asan accelerator grid 3. To this grid any desired modulation signals may be supplied so as to varyin accordance with the strength of the modulation signals the electron density of the electron pencil which is caused to be developed by the cooperative action of the cathode I and the apertured plate member '4 serving as a first anode member within the tube.

To provide for suitable deflection of the generated cathode ray pencil, conventionally designated as 5, there has been provided a plurality of deflecting plate members 6 and I to which 40 deflecting voltages of any desired frequency may be applied.

Toward the end of the tube there-is provided the anode 8 and auxiliary anode assembly I I. The

. anode 8 is composed of a series of rectangular spacing area is preferably in the form of a mesh I'll which extends over the area immediately behind the conducting members 8. The conductas ing members 8, which are preferably formed of nickel suitably carbonized or some otherv material which has low secondary emission properties such as carbonized nichrome, for example, are attached to the open mesh in by welding or other suitable means. The open mesh I0 is preferably formed'of nickel wire which has high secondary emission properties.

In this manner it will be seen from the construction that the anode 8 is formed of alternate strips or areas'of carbonized nickel 9 suitably attached to a sheet or strip of nickel mesh III in such manner that the solid portion and the mesh areas are alternately in the path ofthe electron beam 5 as 16 it is passed or directed across the anode surface I by the application of controlling or deflectingvoltage to the electrostatic deflecting plates 6, I.

Immediately to the rear of the anode assembly 8, above described, there is provided still another 20 anode ll, termed an "auxiliary anode, which is preferably constructed ofa sheet of nickel. This sheet of nickel is so formed as to present a rough surface on the front face. Such a surface which comprises, for example,projecting edges maybe suitably made by punching small holes, or by suitably pressing small holes through from the back and then securing, by welding or any other wellknown means, a second sheet of nickel to the perforated sheet in order to block the perforabe carbonized in order to reduce secondary emis- .sion.

At one end of the envelope I! which encloses the electron gun structure comprising the cathode I, the electron directing member 2, the grid 8 and the apertured plate 4 serving as a first anode forthe tube, are suitably mounted. Operating voltages are supplied to these various elements by way of suitable conductors or wires passing through the press member l3 formed in the end of the tube at which the electron gun is mounted. The cath "de I which emits the electrons to form the cathode ray is preferably indirectly heated, although the operation of the tube is in no way afl'ected if the cathode is heated directly. At the opposite end of the tube envelope l I there is a second stem member II through which lead wires l5 and I6 to supply operating voltage to the two ,separate anode members may be employed. In practice, the anode member II should be operated at a higher potential than the anode member 8. From this construction so far described, it can be seen that when the electron pencil is focused on one of the carbonized strips of the anode member 8, the current to this anode is'high, and con- ,sequently the current to the other anode member I I is low. However, as soon as deflecting voltages are applied to" the deflecting electrodes 8 and I the cathode beam is moved so that it falls upon 00 one of the mesh portions of the anode 8 in which event a'number of the-electrons comprising the electron beam pass throughthe interstices of the mesh and are collected .by the carbonized nickel anode'member II. At the same time other electrons of this same cathode ray beam I strike the mesh wires II and cause the release of secondary electrons from thesewires, of .which a large percentage are attracted to the anode member II. The mesh," should be treated so as-to have the V property of emitting secondary electrons. In

'thecasewhereanickelmeshisemployedthewires should be clean-and have a smooth shiny surface. In this example and under the conditions whentheelectronpencilisstrikingor'passing: 1| throughthemuhportic nthecurrntintheanode' tions. This second nickel anode I;I may then also 8 is reduced to a minimum and the current in the anode I I is a maximum. Conversely, as above defined, the current in the anode I I is a maximum when the beam is focused upon the mesh portions of the anode 8 and a minimum when focused upon a solid portion of the anode 8. So designed, it is quite apparent that the tube herein described will serve, upon deflection of the electron pencil generated from the cooperative action of the apertured plate member 4 and the electron source I, when the two anode members 8 and II are connected with an external circuit, to produce in the external circuit a multiplied frequency of the controlling frequency. The degree of multiplication will be determined in accordance with the number of discrete and independent sections into which the anode 8 is divided so as to distribute conducting and meshlikesections or areas to the electron ray developed within the tube. I

This frequency multiplication may beexpressed mathematically by the equation F=Nsf=(-o1)f where I is the frequency applied to the deflecting plates 6 and 1; Ne is the total number of strips or plates if an even number; No is the total number of screen strips or plates ifan oddnumber; and F is the frequency set up or developed in the external circuit.

If, however, the plates are arranged in a circular order, that is, so each plate is sector-shaped, and alternate plates are of different characteristics, the developed frequency will then be a function of the number of pairs of plates, since for one complete cycle of the impressed frequency the cathode ray beam or pencil will traverseeach segment once. This feature may be expressed mathematically by the. equation F=Py, where? is the frequency set up or developed in the external circuit, P represents the number of pairs of plates, and f is the frequency applied to the deflecting plates to deflect or sweep the cathode ray beam across the plates. I From the above description it is apparent that many modifications and changes may be made without departing from the spirit and scope of this invention and I therefore believe myself to be entitled to make and use any and all of these modifications insofar as they fall fairly within the spirit and scope of the invention to be hereinafter defined in the appended claims.

Having thus described the invention, what I I claim and desire to secure by Letters Patent is the following 1. An electron device comprising a cathode a'second anode formed of-alternate sections having high and low secondary electronic emission properties, an auxiliary anode adjacent the second anode and having low secondary electronic emission properties of substantially the same order as the low. secondary electron emitting portion of the second anode, means for causing the electron beam to traverse the several secelectronic emission properties, a plurality of sections of low secondary electronic emission properties secured to the mesh-like structure and interposed between said structureand the electron source, an auxiliary anode having low secondary" electronic emission properties positioned adjacent said second anode and adapted to receive the electron beam passed through the mesh-like sections of said second anode, and means for causing the developed electron beam to traverse alternately the sections 0! the sec-' ond anode.

3. An electron device for producing variations oi anode currents which comprises a cathode and an anode, a second anode for receivingthe electron beam, said second anode comprising alternately arranged solid and partially solid sections electrically connected, the solid sections being designed to emit a small quantity of sec ondary electrons and the partially solid sections being designed to emit a large quantity of secondary electrons, an auxiliary anode substantiaily adjacent the second anode.

4. An electronic device comprising an envelope including a metallic mesh-like material having relatively high secondary electronic emission properties, a plurality of substantially equal area metallic sections having relatively low secondary electronic emission properties secured to the mesh-like structure and dividing the struc-- ture into alternate sections 'of high and low secondary electronic emission properties, an electron source, and means ior causing the electronic discharge to traverse the several sections of the electrode structure.

5. An electronic tube comprising an envelope including a metallic mesh-like material having relatively high secondary electronic emission properties, a plurality of substantially equal area metallic sections having relatively low secondary electronic emission properties secured to the mesh-like structure and dividing the structure into alternate equal area sections of high and,

low secondary electronic emission properties, an electron source, an auxiliary electrode arranged adjacent the sectional electrode and more remote from the source of the electron discharge, said auxiliary electrode having low secondary electronic emission properties and adapted to be subjected to the action of the electron discharge trically. connected with the multi-section electrode and the auxiliary electrode, and means for moving the electron discharge over the area of the multi-section electrode.

6. An electron device comprising a plurality a electrodes an electronic discharge, a multi-sec-H tioned electrode positioned in the path of the discharge, said electrode having alternate sections of high and low secondary electronic emission properties under the action of the electron discharge, an auxiliary electrode adjacent the multi-sectioned electrode, said auxiliary electrode having low secondary electronic emission properties corresponding to one series of pottions of the multi-section electrode, conductors connecting with said electrodes and extending outwardly through the device so that an external circuit may be connected therewith and become electrically associated with the multi-sectioned electrode and the auxiliary electrode, means for causing the developed. electron discharge to traverse the several sections of the multi-sectioned electrode member. 7

'7, An electronic frequency multiplying device comprising an'electrode structure comprising a metallic mesh-like material having relatively plurality of substantially equal area metallic sections having relatively low secondary elec- .high secondary electronic emission properties, a

tronic emission properties secured to the mesh- 7 an auxiliary electrode arranged adjacent the sectional electrode and more remote from-the source of the electron discharge, said auxiliary electrode having low secondary'electronic emission properties and adapted to be subjected to the action of the electron discharge during time periods concurrent with the subjection oi the area of the first electrode having relatively high ductors arranged within the device and extending outwardly so that an external circuit may be electrically connected with the multi-section electrode and the auxiliary electrode, and deflecting means for moving the electron discharge over the area of the multi-section electrode at a predetermined rate.

8. An electrode structure comprising a plu-- rality of alternate areas of metallic mesh-like sections lying in one plane and alternate solid metallic sections lying in a plane parallel to said first-mentioned plane, said mesh sections and solid sections being electrically connected, the mesh-like sections having the property of emitting secondary electrons in abundance and the solid sectionshaving low secondary emission properties.

' DONAL?!)v GRAYDON HAINES.

secondary electronic emission properties, con-