US2163210A - Braun tube - Google Patents

Description

June 20, 1939. B. WI'ENECKE 2,163,210

BRAUN TUBE Filed Oct. 9. 1936 Ja e/710 Patented June 20, 1939 UNITED ST BRAUN TUBE Steglitz, Germany Application October 9, 1936, Serial No. 104,862 In Germany October 14, 1935 1 Claim.

The subject matter of the invention is a method of operating cathode ray tubes, more particularly for the amplification of alternating potentials intended to act on the cathode ray, and also 5 arrangements for carrying out this method.

According to the invention, one or more of the alternating potentials intended to act on the cathode ray are amplified and/or generated and/or modulated and/or rectified with the aid 10 of one or more discharge paths situated within the cathode ray tube itself.

One or more electrodes of one or more of said discharge paths may belong simultaneously to the path of discharge serving to generate (or di- 15 rectly act on) the cathode ray. In particular the amplifying path of discharge and the path of discharge producing the cathode ray may have a common cathode.

Intermediate of this case and the case in which 20 the amplifying path of discharge and the path of discharge producing the cathode ray have different cathodes (which may be of advantage for some purposes for which the method according to the invention may be employed there is the case 25 in which, though the cathode (heating) element is common to both paths of discharge, the emissive surfaces for the two paths are separate.

In cathode ray tubes, in which the cathode serving to produce the cathode ray is arranged within an encompassing electrode (for example a Wehnelt cylinder), which may serve, for example, for screening purposes and/or concentration of the ray and/or control of the intensity of the ray, there may be provided within this en- 35 compassing electrode one or more paths of discharge for amplification purposes. In a path of discharge provided in accordance with the invention there may be included in addition to the control grid one or more auxiliary grids (screen- 40 ing grid, intercepting grid, etc.), and it is also possible to employ discharge paths of this kind in accordance with the invention, instead of for amplification purposes or in addition thereto, also for other purposes known in connection with 45 discharge tubes, for example for rectification, the generation of the oscillations or for modulation. In the first case, if it is desired to employ in place of an anode or grid rectification a simple valve rectification, the path of discharge may be made 50 bi-polar (of the diode type). According to a further feature of the invention, the coupling elements necessary for the purpose of use of the auxiliary discharge path or paths provided in accordance with the invention may likewise be 55 arranged inside the cathode ray tube.

Two simple examples of arrangements according to the invention are illustrated in the drawing. In each figure of the drawing, there is shown merely one auxiliary discharge path arranged according to the invention, via, a three pole amplifying path, serving in the arrangements shown in Fig. l for the amplification of deflecting potentials, and in Fig. 2 for the amplification of intensity control potentials.

The coupling elements are shown in all figures as being provided within the cathode ray tube.

In the drawing l is the bulb of the tube, 2 the cathode member having the emissive surface 3 serving to produce the cathode ray, 4 an encompassing electrode, 5, 6 and l are additional electrodes which act as accelerating electrodes and/or elements of the electronoptical arrangement, 8 and 9 are deflecting electrodes, and Ill (in Figs. 1 and 2) is an emissive surface which is acted upon by the same heating element as 3 and belongs to the path of discharge serving for amplification purposes. H is the appertaining anode, and [2 (in all figures) is the control grid provided in the auxiliary path of discharge;

I3 is a luminescent screen structure shown as being of the well known conventional type; the leads K, H, W, A1, A2 and G serve for supplying the heating (preferably alternating) potential, the direct potentials for the system electrodes and the alternating potentials to be amplified. The amplified alternating potenials are tapped at the anode resistance Ra and by way of the coupling condenser C are conducted in the arrangements according to Fig. 1 to a deflecting plate and in the arrangement according to Fig. 2 to the encompassing electrode (Wehnelt cylinder). H

is the leak resistance for the electrode to which the amplified potential is conducted.

In Figs. 1 and 2 the auxiliary path of discharge has a special cathode-emission surface which, however, is provided on the same cathode (heating) element as the emissive surface serving to produce the cathode ray. The entire auxiliary path of discharge is provided within the encompassing electrode 4.

The lead P in Fig. 2 serves for supplying the deflecting alternating potentials.

Naturally the method according to the invention may also be applied to cathode ray tubes of greatly varying construction and for the most different purposes, including more particularly those Braun tubes which are employed for oscillographic, television or sound-film purposes.

I claim:

In a cathode ray tube comprising a beam gun as anode, beam deflecting plates and an inside heated cylindrical insulator supporting the ray cathode and being surrounded by a cylindrical electrode, said insulator supporting a second cathode forming, in cooperation with a cylindrical grid and a cylindrical anode arranged inside of said cylindrical electrode, a thermionic amplifier, said both cathodes being connected with each other and said cylindrical anode being connected through an anode resistance arranged inside of said cathode ray tube to said beam anode, and through a condenser being arranged inside of said cathode ray tube to one of said deflecting plates, said grid being adapted to be connected to the scanning potential.

BRUNO WIENECKE.

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