US2879443A

US2879443A - Electronic device

Info

Publication number: US2879443A
Application number: US553269A
Authority: US
Inventors: Aiken William Ross
Original assignee: Kaiser Industries Corp
Current assignee: Jeep Corp
Priority date: 1955-12-15
Filing date: 1955-12-15
Publication date: 1959-03-24
Anticipated expiration: 1976-03-24

Description

7 March 24, 1959 V w. R. AIKEN ELECTRONIC DEVICE Fiied Dec. 15, 1955 3 Sheets-Sheet 1 E vw INVENTOR. WILL/AM ROSS AIKEN B zLw March 24, w R AlKEN ELECTRONIC DEVICE 5' Sheets-Sheet 2 Filed Dec. 15; 1955 INVENTOR. W/LL/AM R058 AIKEN Mww mw R

March 24, 1959 w. R. ALKEN 2, 9,

ELECTRONIC DEVICE Filed Dec. 15, 1955 I I 3 Sheets-Sheet 3 7 INVENTOR. W/LL/AM Ross A/KEN a or Un ed S s P m? ELECTRONIC DEVICE Ross Aiken,'Los Altos, Califi, assignonby mesne assignments, to Kaiser Industries Corporation, a corporation of, Nevada v v The present invention relates to cathode-ray tubes and more particularly to an improved electrostatic deflection system for increasing the deflection angle of an electron beam. 'One'of the problems attendant in the employment and utilization of cathode-ray tubes presently known in 'the 'art, including the conventional elongate type and the relatively'recently developed flat tube of the Aiken type as disclosed in copending application's Serial No. 396,120, which was filed December 4, 1953, issued June 11', 1957, as Patent No. 2,795,731, and Serial No. 355,965, now

abandoned, which was filed May 19, 1953, is achieving alarge deflection angle for the electron beam. Manifestly, when the electron gun is disposed reasonably close to the target screen of a cathode ray tube, a large de} fl'ectio'n angle is necessary in order to effect a complete I 2,879,443 Patented Mar. 2 495? A curved slotted electrode is disposed between the high voltage section of the tube, and the electron gun. It lis possible with this arrangement to provide two substantially discrete voltage zones; one between the electron gun and the slotted electrode, and a second voltage zone between the slotted electrode and the high voltagesection. 1

In operation, the first of the said voltage zones is maintained at a relatively low voltage value and the second is maintained at a higher voltage value. Inasmuchas' the electron beam initially travels in the relatively lowfvoltage zone, a relatively small amount of power is required to etfect deflection of the beam therein. Accordingly, very large deflection angles may be achieved with low power consumption in the low-voltage zone prior to the instant the electron beam is caused to pass through the slotted electrode and travel toward the relatively high voltage zone. A more complete understanding of the invention may be had from the following description read in connection with the accompanying drawings, wherein:

Figure 1 is a front view of one embodiment of the invention,

Figure 2 is a sectional view of the tube taken along line 22 of Figure l, j

Figure 3 is a perspective view of the slotted electrode.

Figure 4 is a diagrammatic illustration of another modification of the instant invention showing an electrode eriergization of the target. As presently understood, defle'ction angles of the order of approximately 90 are art after reading the following description. One of the applications of the invention is in connection wtih navi- 'gational aids such as radar. During the recent past, radar systemshave played an increasingly more important part in controlling the flight of aircraft and in aiding the navigation of many other types craft.

Of course, one

of the ever existing tasks in the development ofv aircraft is the curtailment of-the space or volume requirements of the operating components and their associated control mechanism. The instant invention has produced a tube of the cathode ray type which can be economically consume a relatively smaller volume than the conventional tubes, while at the same time the viewing screen 'need not be curtailed in the slightest. Advantages such as thes'e'are made possible by the instant invention-in that acathode ray tube of the type hereinafter desciibed'is capable of achieving large deflection angles while main taining beam focus throughout the entire deflection of the electron beam.

arrangement adaptable for the presentation of asubstantially rectangular raster.

Figure 5 is a front view of another embodiment of the invention showing an electrode arrangement adaptable for the presentation of an arcuate raster.

In one embodiment of the invention shown in Figures 1 and 2, there is a flat cathode ray tube of theAiken type having an evacuated envelope 10. An electron gun 12 of the conventional type having electrostatic deflection plates 16 is adapted to be disposed within the reduced neck portion of the envelope 10. The deflection plates 16 are provided with electrical conductors 18 which serve to electrically couple the deflection plates 16 to any source of energizing potential. The electron gun 12 is adapted to deliver an electron beam 14 which passes be tween the deflection plates 16. I

An electron sensitive target 30 is disposed in 'a plane which is substantially parallel and slightly spaced from the plane of initial travel of the electron beam 14. The target 30 may be formed by depositing a fluorescent'rnaterial on the inner surface of the envelope 10 in any of the manners well known in the art. The target '30 'is provided with an electrical conductor 32 which suitably affects an electrical coupling between a power supply outmanufactured and employed in radar systems, andfwill side of the envelope 10 and the target 30. A plurality of preferablytransparent electrically conducting deflection electrodes 26 are positioned in a coextensive manner with respect to the target 30 and spaced therefrom amount sufiicient to permit the electron beam 14 to travel therebetween. The transparent deflection electrodes 26 In one embodiment of the invention, certain of the the deflectionelectrodes 26 are provided eachlwith' an' Aiken tube deflection principles set forth in the copending applications mentioned above are employed. The em bodiment' comprises a target screen and a set of high voltage deflection elements substantially coextensive with and slightly spaced therefrom, which assembly will be referred to as the high voltage section. An electron gun of the conventional type, having electrostatic deflection plates, is disposed inclose proximity with respect to the high voltage section and is adapted to deliver 'a relatively low vol tage beam of electrons along a'path in adirec'tion towardsaidsection, 4

are suitably aflixedas will be manifest in Figure 2 to the inner surface of the envelope 10 opposite the'surface on which the target 30 is aflixed.

As will benoted from an examination of Figure'l,

electricalconductor 28 which is adapted to extend through the envelope 10 to an electrical generator situated outside thetube. I

A curved electrode 20 is disposed between the .high

" .5 voltage section, consisting of the target 30and its;,a ssociated deflection electrodes 26, and the electron gun 12. A slot or aperture 24 is formed in the electrode ZO-ancl extends substantially thelentire length thereo fasis clearly illustrated .in Figure 3. The slot 24".is. positioned, ,suglt that the electron beam 14 emitted from the electron gun tions 'of'the electrode 20 function as the actual limits of the beam sweep; that is, the beam 14 may be eflec tively caused to oscillate or sweep to and fro within the slot 24 and any electrons which tend to exceed the slot length will impinge and be effectively stopped by the solid terminal portions of the electrode 20. As. shown in this embodiment, electrode 20 is curved so as to become a radius of the deflected'beam. Thus, as the electron beam passes through curved electrode 20, said electrode will be at all times tangential to said beam and cause no further deflection of the beam as it is accelerated from the low voltage to the high Voltage region. Also, it will be noted that an electrical conductor 22 is provided with one end in electrical contact with the electrode 20 and the other, end leading to a powerv supply outside the tube envelope 10, not shown.

In the operation of the embodiment described hereinabove, electron gun 12 is preferably operated at about 1 kv. and slotted electrode is operated at approximately the same potential. The deflection electrodes 26 and the target screen 30 are maintained at about 10 kv. It will now be readily discernible that the voltage zone established in the region defined by electron gun 121 and slotted electrode 20 is lower, by a factor of 10, than the zone defined by the high voltage region consisting of deflection electrodes 26, target 30, and slotted electrode 20, It will be readily apparent that the powerrequired to deflect the electron beam 14 in the low voltage region is much less than the power that would be necessary in the event the beam were deflected in a high voltageregion such as that existing in the region of the target 30.

As the electron beam 14 passes between the electrostatic deflection plates 16 it may be caused to oscillate to and fro by the application of suitable varying potentials on these deflection plates. The beam will then pass through the slot 24 formed in the electrode 22 and pass intermediate the deflection electrodes 26 and the target 30 in the field-free region established therebetween. The electron beam may be deflected toward and impinge upon the target 30 upon suitable lowering of the voltages'on one or more of the deflection electrodes 26. When the electron beam 14 is caused to impinge upon the fluorescent material of the target 30, the fluorescent material becomes excited and will emit a visual signal in the form of light. Upon suitable synchronization between the potentials applied to the deflection plates 16 and the deflection electrodes 26 a complete raster may be formed over the entire target area.

In order to achieve an even greater deflection angle of the electron beam 14 after it has been deflected by the deflection plates 16, the electrode 20 maybe curved in a manner such that the centerof curvature would reside at. a-- point within the zone intermediate the deflection plates 16 and the curved electrode 20. The electric field established by this change in curvature of the electrode will cause the beam 14 to oscillate about the center of curvature of the electrode 20. The beam 14, as it passes through the slot 24 formed in the electrode 20, encounters the high voltage zone residing between the curved electrode 20 and the target 30 and its associated deflection electrodes 26. This higher voltage on the side ofthe electron gun 12, the electrostatic deflection plates 16, the slotted electrode 20, the transparent deflection electrodes 26, and the target 30, aresubstantially identical in arrangement with those shown and described in connection with Figures 1 and 2. It will be noted that an addi tional electrode 34 is provided and it is suitably disposed in the region between the slotted electrode 20 and the high voltage section. The electrode 34 is slotted in a manner similar to the electrode 20 but bowed in an opposite direction and is provided with an electrical-conductor 36 which is adapted to extend through the tube envelope 10 to a power supply situated outside the tube.

Inoperation, the potential applied to the electrode 34 is slightly higher than the potential value impressed on the electrode 20 and the electrostatic field established thereby in conjunction with the electrostatic field established by the electrode 20 tend to cause the beam to straighten and assume paths which are substantially parallel to; one another, thereby enabling a rectangular display on the target 30. The manner in which the beam 14 is deflected to impinge on the target 30 is identical with that described hereinbefore in connection with Figures 1 and 2.

It must be pointed out here that the arrangement shown in Figure 4 has an ancillary use in connection with the focusing of the electron beam 14. This arrangement also tends to focus the beam in a plane normal to the plane of the target which is due to the curvature of the

electrodes

20 and 34 such that the electrons on one side of the beam enter the field defined by each of the elec trodes at a different angle than do those onthe other side of the beam. This effect is similar to and analogous to an optical lens arrangement. Manifestly, byadjusting the curvature of either the electrode 20 or the electrode 34, singularlyor inconjunction with one another, they can be made to focus or defocus the beam. All of the effects which have been set forth above will be apparent in the same structure, and all focus and deflection adjustments will interact so that it is diificult to separate the various actions.

In order to achieve a useful display in some types of radar installation, it is desirable to have the angular width of the scan remain constant. This means that as the range increases, the radar image must be seen on an increasingly larger width of display area. In the modification shown in Figure 5, this type of radar display is achieved. The arrangement of components, including electron gun 12, electrostatic deflection plates 16, slotted electrode 20, and the target 30 are substantially identical in arrangement with those shown and described in connection with the other embodiments. It will be noted, however, that the deflection electrodes 56 are arcuate segw ments and have increased length as they are further reelectrode 20 away from the electron gun 12 will act to bender-deflect the beam at an even greater angle than itxwas deflected by the electrostatic deflecti0n'plates-16.

It "is readily discernible that the'utilization of the-device-described in cathode ray tubes will providea-relatively large sector scan with the use ofrelatively low beam deflection voltages.

Howeverrif it is desired touse the described device tmobtain, a. substantially rectangular-raster, this may be readily accomplished or achieved by supplementing one additional electrode as shown inFigure 4., As, there shown, the arrangement. of components. including the.

movedfrom the electron gun. The entire structureis placed within an accommodating envelope 50. If the display is to be viewed from both sides of the tube, then the deflection electrodes 56 should be transparent.

In operation, the potentials applied to the electrodes are within the range of those described in connection with Figures 1 and 2. All of the etfectswhich have been set forth above will be apparent in thisstructure and all focus and deflection adjustments will be approximately the same.

What is claimed is:

1. In an electron discharge device an electron beam source means adapted to deliver a beam in a given plane, an accelerating means for said beam comprising a first electrode means comprising at least one curved electrode disposed along the beam path to present a concave surface relative to the beam direction of travel, and a sccondelectrode 'means comprising-at least one curved electrode disposed at a subsequent point along the beam path to present a convex surface relative to the. beam. direction of travel. 2. An arrangement as set forthin claim 1 whichjn:

eludes means for supplying a potential to said first electrode of a first value and means for supplying a potential of a higher value to said second electrode.

3. In an electron discharge device a target, an electron beam source meansadapted to deliver a sweep beam in a given plane substantially parallel to said target, an accelerating means disposed along the sweep path of said beam comprising at least one curved electrode member for accelerating the beam in its travel in said plane, and a set of curved deflection plates for deflecting said beam from said plane into registration with said target.

4. In an electron discharge device, a target, an electron beam source means adapted to deliver a beam along a given path in a plane substantially parallel to said target, means for deflecting said beam from said path to a second path in said plane, accelerating means disposed along the deflected path of said beam for accelerating the beam travel along the deflected path, an electrode member disposed along the beam deflected path for deflecting said beam to a path substantially parallel to its initial path, and deflection means for deflecting said beam from said last path into registration with said target.

5. In an electron discharge device, an electron beam source means adapted to deliver a beam along an initial path in a given plane, deflection means for deflecting the beam to different paths in said plane which are angularly disposed from said initial path, and accelerating means for said beam including a first electrode means having a first surface which is substantially perpendicular to each of said beam paths, and a second electrode means of a configuration which is complementary relative to said first means for deflecting the beam subsequent to its passage through said first and said second electrode means to paths parallel and offset to said initial path.

6. In an electron discharge device, an electron beam source means adapted to deliver a beam along an initial path in a given plane, deflection means for deflecting said beam from said initial path to a second path angularly displaced therefrom, a first electrode means comprising at least one curved electrode disposed along the beam path to present a concave slotted surface relative to the beam direction of travel, and a second electrode rneans comprising at least one curved electrode disposed at a subsequent point along the beam path to present a convex slotted surface relative to the beam direction of travel, the relative radius of curvature of said first and second electrodes being of a value to deflect said beam from its displaced path to a path in substantially parallel offset relation to said initial path.

7. In an electron discharge device, a target, an electron beam source means adapted to deliver a beam along a predetermined path in a given plane which is substantially parallel to said target, deflection means for deflecting the beam from said first path to difierent adjacent paths in said plane, an accelerating means for said beam comprising a first electrode means comprising at least one curved slotted electrode disposed along the beam path to present a slotted concave surface relative to the beam direction of travel along said diflerent paths, and a second electrode means comprising at least one curved slotted electrode disposed at a subsequent point along the beam path to present a convex surface relative to the beam direction of travel subsequent to its passage through said first slotted electrode, the relative radius of curvature of said first and second electrode means being of a value to deflect said beam to a path subsequent to its passage through said second electrode means which is parallel to its initial path and in spaced adjacent relation with said target, and secondary deflection means for deflecting said beam from its latter path into selective registration with said target.

8. In an electron discharge device, a target, an electron beam source means adapted to deliver a sweep beam in a given plane substantially parallel to said target, an accelerating means disposed along the sweep path of said beam comprising at least one curved electrode member for accelerating the beam in its travel in said plane, and a set of arcuate deflection plates disposed in a plane spaced from and substantially parallel to said target for deflecting said beam from said plane into selective registration with said target, each of said deflection plates having its concave surface disposed in the direction of the beam travel.

9. In an electron discharge device, means for establishing a first voltage zone, means including an electron sensitive target and a second deflection electrode set disposedin spaced relation with said target to establish a second voltage zone therebetween which is of a greater value than said first zone, an electron beam source means for delivering a beam along a path which extends successively through said first zone and into said second zone between said second deflection means and said target, an arcuately shaped accelerator member disposed between said first and said second zones including a control slot in said accelerator member aligned with the beam path to control the beam velocity in its passage therethrough, and means for applying energizing potentials to said second deflection electrode set to effect selective deflection of the beam from its path into registration with said target.

References Cited in the file of this patent UNITED STATES PATENTS 2,053,537 Schlesinger Sept. 8, 1936 2,114,572 Ressler Apr. 19, 1938 2,239,407 Wagner Apr. 22, 1941 2,289,319 Strobel July 7, 1942 2,348,133 Iams May 2, 1944 2,449,558 Lanier et al. Sept. 21, 1948 2,513,742 Pinciroli July 4, 1950