US2876374A

US2876374A - Electronic tube structures

Info

Publication number: US2876374A
Application number: US500430A
Authority: US
Inventors: Theodore K Riggen
Original assignee: Corning Glass Works
Current assignee: Corning Glass Works
Priority date: 1955-04-11
Filing date: 1955-04-11
Publication date: 1959-03-03
Anticipated expiration: 1976-03-03
Also published as: CH344488A; GB808292A; DE1077791B; BE546906A

Description

Max-c113, 1959 T. K. RIGGEN 2, 7

' ELECTRONIC TUBE STRUCTURES Filed April 11, 1955 2 Sheets-Sheet 1 INVENTOR. 7000z A? 19/665 WW nmPme March 3, 1959 T. K. RIGGEN 2, ,3

' ELECTRONIC TUBE STRUCTURES v Filed April 11, 1955 2 Sheets-Sheet z ELECTRONIC TUBE STRUCTURES Theodore K. Riggen, Elmira, N. Y., assignor t 'Corning glais Works, Corning, N. Y., a corporation of New Application April 11, 1955, Serial No. 500,430

11 Claims. (Cl. 313-102) This invention relates to electronic tubes of extremely small size, and more particularly to a design for such tubes that lends itself well to multiple tube elements as a single manufactured piece.

The present state of the electronic arts requires miniaturization 'of all its components. A further requirement is that the several components be so designed that multiple elements can be manufactured. An example of this type of design is the trend to printed circuits and modular construction. It is the prime object of this invention to so change the basic design of electron tubes that these conditions will be met. Electron tubes, as currently being produced, consist of small metallic parts (usually welded together) encapsulated in a hermetically sealed container. The minimum sizes in which they can be made is dictated by the sub-assembly of the metallic parts and the physical handling thereof. The inability to multiplex these units is inherent in their individual encapsulation. The present invention avoids both these parameters by the nature of its design which can best be understood by referring to the accompanying drawings wherein:

Figure 1 shows an exploded view, in perspective, of a single diode built on the principles of the present invention.

Figure 2 is an exploded view, in perspective, of a triode of the same design.

Figure 3 is an exploded view, in perspective, of a grid controlled indicator tube of like design.

Figure 4 is a cut-away view of a multiple element array of indicator tubes with dual grids for control.

Figure 4a is a circuit diagram applied to elements of the structural arrangement of Figure 4.

Figure 5 is a cross-sectional view of the unit shown in Figure 2, assembled.

Figure 6 is an application of the triode of Figures 2 and S to a common type of resistor-coupled amplifier circuit, with the supports for the several elements of such triode omitted to simplify the showing;

Figure 7 shows a circuit, similar to that of Figure 6, employing a conventional triode.

Referring now to the diode shown in Figure l, 11 is a supporting member of some stable insulating material such as glass; 12 is an electron emissive coat on the fore face of 11. This may be a semi-transparent photoemissive coat adapted to receive exciting light through support 11 from the opposite side thereof; it may be a thermo-emissive coat adapted to receive infra-red radiation through the supporting member; or it may be thermoemissive, heated by aiesistance coat (not shown), on the same face of the support. A conducting foil, 13, is atfixed to the electron emissive coat and acts as the cathode connection of the diode. A spacer plate 14 separates the cathode 12 from an anode supporting plate 16 the desired distance. A hole 15 in plate 14 allows electrons from cathode 12, to pass to an anode 17, which is sealed in plate 16.

atent ice Plate 28 has a hole 29 in register with a hole in plate 24, and bears foil 20 which surrounds hole 29 and extends beyond an edge of plate 28. Foil 20, when held at a negative potential, acts as a gate, or grid, to regulate the number of electrons passing from the cathode 22, to an anode 27 supported by a plate 26, similar to plate 16.-

Hence a triode is obtained. The addition of a second member similar to that formed by

elements

20, 28 and 29 could yield tetrode action, etc., as will be understood by those familiar with the construction and operation of electron valves or tubes.

In Figure 3, a plate 36, which bears a fluorescent powder coating 32 on the side next to a plate 34, replaces the plate 26 of Figure 2. This coating is of the conducting type and connection'to it is made through a foil 33.

Elements

31, 34 and 38 are like the

elements

21, 24 and 28 of Figure 2.

In Figure 4 (Sheet 2), the plate 411 bearing'fluorescent coating 412, connected to foil 413, is functionally similar to the like elements in Figures 1-3. Plate 41, having holes such as 45, is substantially as described in Figure 1.

' Plate 48, having holes 49 surrounded by grid electrodes grammatically shown with push button switches B1-B14 associated with their respective grids, normally placing a negative bias thereon.

In Figure .5 (Sheet 1) the unit shown exploded in Figure 2 is illustrated assembled, and has its corresponding elements designated likewise. This is, then, indicative of the other embodiments of the present invention in assembled form whether they be of the single or multiplex type. A material such for example as solder glass 50 has been added to seal the lines of juncture of the several plates together after evacuation. The respective plates may, however, be directly sealed to one another providing the dielectric material used has a low enough softening temperature to enable the sealing of their adjoining-surfaces to one another without harm to the coatings thereon. Under such circumstances, where some types of coatings are used, to assure obtainance of hermetic seals between the coated and uncoated plates it is necessary that the outer margins of the coating terminate a short distance from the plate edge so that glass-toglass contact is obtained. A further alternative is to employ a form of encapsulation of the several forms currently in use in vacuum tube practice. From the showing in Figure 5 it will be noted that the inner end of the anode 27 terminates short of the entrance to a pocket 51 in plate 26. Obviously, if desired, a plate similar to 26, having the added thickness of spacer plate 24, can be employed in lieu of plates 24 and 26, thus reducing the number of joints in the seal. The operation of a single cell tube can best be explained by references to Figures 5 and 6.

Light striking through plate 21, Figure 5, causes electrons to be emitted by photo-emissive cathode 22. These electrons will proceed at random velocities and directions away from cathode 22 in the evacuated space left .by holes 29 in. plate 28, and 25 in plate 24 and/or pocket 51. If the anode 27 is held at a positive potential, with respect to the cathode 22, the emitted electrons will be drawn to the anode, 27 and a current will be established. A controlled potential applied to grid foil'20 will control the flow of electrons from the cathode 22 to the anode27. The action of a circular grid member is well understood by those acquainted with cathode ray tube electron guns. "7

For a comparison of a co ventional circuit employing a tlide tube embodying the invention with a tube of conventional form, reference is had to Figures 6 and 7. In Figure 6 a light source L, powered by a battery 6A exciters the photo cathode 22. In Figure 7 a heater H,

powered by a battery 7A, excites the therrno-emissive cathode K. In Figure 6 a battery 63, through a load resistor, 6R2, maintains the anode 27 at a positive potential with respect to the cathode. In Figure 7 a battery 73, through a load resistor 7R2, eflects the anode P in a similar fashion. In Figure 6, a battery 6C, through a resiSiO F 6R1, maintains the grid 20 at some optimum negative bias with respect to the cathode. In Figure 7 a battery 7C, through a resistor 7R1, effects the grid G in a similar fashion. Now, if an A. C. voltage signal be impressed across the input points, GIN or 7IN, and read across the output points, 6OUT or 7OUT, it will have been amplified by the gain of the system.

In the case of the triode circuit in Figure 7 the gain of the system is, in part, a function of the potentials applied, the component values used, the geometry of the triode and the emissive ability of the cathode in the triode. The same parameters hold for the triode used in Figure 6. I

The geometry of the new design tube may be altered by changing the size of the holes, by expanding the inner endof the anode wire to a disc equal to the hole size, and by regulating the thickness of the grid supporting and spacer plates.

If a relatively high current unit is desired, necessitating the use of larger plates, the grid supporting plate having a single hole may be replaced with one having a group of small holes with but a single foil surrounding and interconnecting them, so that the portion of the plate bridging adjacent holes in the grid will serve as a mechanical support for the large area of the adjacent cathode plate during evacuation and sealing of the unit.

In the embodiment of a multiplex of units as shown in Figure 4, the holes in

plates

41, 48 and 414 are in line to'allow electrons emitted by the cathode 412 to pass through to the fluorescent anode 42 on the inner side of plate 46. The strip grid connections or foils 410 and 416 are continued past their supporting

plates

48 and 414 in a fashion similar to the single unit grid 28 in Figure 2. This multi-element unit can be used for the selective display of several indicator spot signals. Similarly such a unit employing individual anodes, such as 27, may .be employed in selective control circuits as hereinafter described.

By Way of example, with respect to selective indicator signals, reference is had to Figure 4a wherein plate 414 has a bank of forty-nine holes divided into seven rows of seven holes each, with its grids 416 horizontally connected. Each row of grids 416 is normally held sufficiently negative with respect to the cathode 412 (Figure 4) to prohibit the passing of electrons from the electronemissive coating 412 on plate 41, by negative potential supplied to it through the back contacts of a push button, such as B1, of the group B1B7. Similarly plate 48 has its grids 410 vertically connected in seven rows nega tively biased through break contacts of push buttons B8-B14. As will be evident any one or more .of the push buttons of the respective push button groups may be operated to selectively remove the negative bias from any row or rows of holes in either of the

multi-element grid plates

48 and 414 to permit electrons to pass through the particular holes in register with one another and from which the grid bias has been removed. By way of example, if buttons B1 and B8 are depressed electrons will be permitted to pass through holes X and Y, and when they strike the anode or fluorescent coating 42, the spot or spots on the anode opposite such holes will fluoresce and thus give an indication of the vertical and horizontal row or rows of grids thatare not biased down. Obviously the showing of the grid control circuits as passing through push buttons is for simple illustrative purposes only. As is well known, there are numerous ways in which the grid bias can be removed in any desired combination to selectively give a number of different indications limited only by the number of separate electronic tube units embodied in the assembly.

Alternatively, the multiplexing mayemploy individual anodes, such as 27, and follow a pattern in conformance with a desired specific circuit control need. For example the unit may contain a single row of cells arranged to register with the holes in a teletype-writer tape so that light passing through the tape holes selectively activates the cells as it passes thereover to selectively energize printer control relays of the system.

A further alternative arrangement may embody both the individual anodes such as 27 and a fluorescent coating such as 42, to give a visual signal of the circuit control being exercised.

In addition, as will be evident, if desired the several plates of dielectric material of the-assembly may be utilized as the supports for simple printed circuits in which such cells may be included.

What is claimed is:

1. An electronic tube comprising a stack of plates of insulating material one outer plate of such stack having on its inner surface a cathode comprising a coating of an electron emissive material, said coating having a lead conductor connected thereto and extending laterally therefrom, the oppositely disposed end plate having an anode exposed on the opposite broad surface thereof, and an intermediate plate of said stack spacing the anode and cathode a predetermined distance from one another, said intermediate plate having a passage therethrough providing a path for the flow of electrons between the cathode and the anode.

2. An electronic tube such as defined by claim 1, wherein the stack includes an electron gate comprising a plate of electric insulaitng material arranged between the cathode and the intermediate plate and having a passage therethrough in register with the intermediate plate passage, said electron gate plate having on the side thereof facing said intermediate plate a conductor bordering its passage and extending beyond the edge of such plate to make it available for the receipt of a negative potential to regulate the number of electrons that are permitted to pass between the cathode and the anode.

3. An electronic tube-comprising a stack of plates of electrical insulating material one end plateof such stack having on its inner surface a cathode comprising a coating of an electron emissive material, the oppositely disposed end plate having on its inner surface an anode comprising a coating of a fluorescent material, said coatings having lead conductors connected thereto and laterally extending therefrom, a spacer plate arranged between said end plates having an aperture therethrough for the passage of electrons between said anode and cathode.

4. An electronic tube such as defined by claim 3 wherein the stack includes. a plate interposed between the first defined end plate and said spacer plate having a layer of conductive material thereon surrounding a passage therethrough in register with the spacer plate passage on the side adjacent the spacer plate, said conductive material extending from the edge of such plate to make it available for the receipt of a negative potential to regulate the number of electrons that are permitted to pass between the coated surfaces of the end plates of the stack.

5. An electronic device including plates of an electrical insulating material forming the opposite end plates of a stack thereof, one of said end plates having a cathode comprising a semi-transparent photo-emissive coating on its inner surface, the other ,end plate having an anode on ts inner surface comprising a fluorescent coating, a spacer plate included in said stack, two electron gate supporting plates arranged adjacent one another between said spacer plate and one of the end plates, said spacer plate and said electron supporting gate plates having a plurality of apertures in register with one another and providing a number of separate electron paths between said end plates, and means for selectively controlling the flow of electrons through such passages to excite corresponding surface areas of the anode.

6. In an electronic tube, a stack of flat plates of an electrical insulating material hermetically sealed together, a cathode arranged on the inner surface of one end plate of such stack, an anode supported by the opposite end plate of the stack, and a spacer plate between said end plates having an aperture providing an electron path between said end plates.

7. An array of electron tubes wherein the like electrodes of all the tubes are carried on a single plate of insulating material.

8. In an electronic tube, a plate of an electrical insulating material having on one broad surface a cathode coating, a second plate having a pocket in a broad surface thereof opposite said cathode coating, and an anode passing through the latter plate having an end terminating Within said pocket short of its entrance.

9. An electronic device including plates of an electrical insulating material forming the opposite end plates of a stack thereof, one of said end plates having a cathode comprising a semi-transparent photo-emissive coating on its inner surface, a plurality of anodes supported by said other end plate, a spacer plate included in said stack, two electron gate supporting plates arranged adjacent one another between said spacer plate and one of the end plates,

said spacer plate and said electron supporting gate plates each having a plurality of apertures in register with one another and in register with said anodes providing a number of separate electron paths between said first end plate and said anodes, and means for selectively .controlling the flow of electrons through such passages to selectively excite difierent ones of said anodes.

10. An electronic device such as defined by claim 9, wherein said other end plate is also provided with a fluorescent coating which fluoresces in the region surrounding the excited anode or anodes to visually indicate the selection made.

11. An electronic tube such as defined by claim 1 wherein the respective plates of the stack have oppositely disposed flat parallel surfaces in engagement with one another and have border outlines in the same vertical planes, and a layer of material bridging the respective layers of the stack and sealing the regions thereof surrounded by such material and between the inner surfaces of the end plates thereof to atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 2,099,531 Passarge Nov. 16, 1937 2,297,492 Michaelia Sept. 29, 1942 2,449,493 Longini Sept. 14, 1948 2,533,809 Hershley et al Dec. 12, 1950 2,592,683 Gray Apr. 15. 1952 2,645,712 Rajchman et al July 14, 1953 2,657,309 Gray Oct. 27, 1953 2,754,445 Sorg July 10, 1956