US2919378A - Static electronic lens for electron beam valves - Google Patents
Static electronic lens for electron beam valves Download PDFInfo
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- US2919378A US2919378A US410619A US41061954A US2919378A US 2919378 A US2919378 A US 2919378A US 410619 A US410619 A US 410619A US 41061954 A US41061954 A US 41061954A US 2919378 A US2919378 A US 2919378A
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- electrode
- lens
- electrodes
- inner electrodes
- diameter
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
- H01J29/58—Arrangements for focusing or reflecting ray or beam
- H01J29/62—Electrostatic lenses
- H01J29/622—Electrostatic lenses producing fields exhibiting symmetry of revolution
- H01J29/624—Electrostatic lenses producing fields exhibiting symmetry of revolution co-operating with or closely associated to an electron gun
Definitions
- the first anode behind the Wehnelt cylinder is followed by a tubular second anode; behind the latter is arranged, at a definite distance of one or several centimeters, another coaxial tube which is fed, as is the first one, with the high anode voltage (A -voltage).
- a -voltage high anode voltage
- a third tube is arranged, the length of which corresponds approximately to the distance between the two anode tubes, and the diameter of which is several millimeters larger than that of the anode tubes.
- This intermediate tube is either fed with a positive voltage which is in comparison much lower than the anode voltage or joined directly to the cathode.
- the intermediate electrode can be either just as long as the distance between the two anode tubes or a little longer or shorter.
- d is the diameter of the anode tubes and D the somewhat larger diameter of the intermediate tube, the desired electrostatic lens effect will be most perfectly achieved when the quotient d:D has a definite value. In the usual electrode systems this value amounts to about 0.7 to 0.9.
- the diameter d of the anode tubes is usually fixed at from to millimetersand the di-. ameter D of the intermediate electrode at from 12 to millimeters.
- the inventor has noted, particularly when working at constructional development, that it is of advantage to combine the whole static electrode system described above in such a manner that instead of the single tubular electrodes being mounted, as hitherto, on glass or other insulating rods arranged parallel -to the tube axis, the whole system is designed as one integral member. a design will be accomplished the better the lighter .the individual static electrodes are, which were described above and which form the lens system. Contrary to this condition is the other condition, mentioned above, that the diameter d of the external anode tubes must not be smaller than a fixed value.
- the present invention advantageously surmounts the difficulties which thus arise. Incontestable experiments have shown that to maintain the required ratio of d to D, it is only necessary to provide this diameter d at those points of the anode tubes which are directly at the origin of the lens fields, i.e. at the transition to the edges of the intermediate electrode. The diameter of the rest of the anode tubes, however, is unimportant for the production of the lens effect.
- the anode tubes of an, in particular, tripartite static system of electronic lenses are provided with a much smaller diameter than hitherto, in particular with a diameter that can be substantially smaller than the diameter D of the tubular intermediate electrode.
- the anode tubes are provided with a funnel-shaped enlargement at the ends near the intermediate tube and have for the rest of their length only a relatively small diameter of a few millimeters.
- the drawing shows one example of this invention, in a simplified arrangement of the three electrodes belonging to a static lens system of the common manner of operation:
- the tubular intermediate electrode .1 which is kept on a low voltage has a diameter D of a normal size of from 15 to 20 millimeters. edges of the two tubes 2 and 3, which are kept on a high 2 potential whereby, at the transition points 4 and 5 and in Such the familiar manner, the static fields which give rise to the lens elfect are formed.
- the tubes 2 and 3 which must, at the transition points 4 and 5, have a definite diameter d that must not be much smaller than the diameter D, are enlarged at 6 or 7 in a funnel shaped fashion, so that the exterior edge of the funnel attains the required diameter d.
- the rest of the anode tubes 2 and/or 3 has a much smaller diameter of e.g. only a few millimeters. This small diameterneed only be large enough to allow the beam, which has not yet been deflected at this point, to pass without touching the walls of the tubes 2 and 3.
- An electrostatic lens arrangement comprising, in combination, a pair of tubular, axially aligned, inner electrodes, each of said electrodes having a body portion and an outwardly flaring end portion, said end portions being located opposite and spaced from each other; and an outer, tubular lens electrode arranged coaxially with said inner electrodes and enclosing the space between said outwardly flaring end portions and at least said outwardly flaring end portions themselves, whereby the opposite ends of said outer lens electrode are relatively widely spaced from the respective body portions of said inner electrodes, and the danger of corona discharge from said opposite ends to the respective inner electrodes when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes is substantially lessened.
- An electrostatic lens arrangement comprising, in combination, a pair of tubular, axially aligned, inner electrodes, each of said electrodes having a body portion and an outlwardly flaring end portion, said end portions being Opposite its external edges are the located opposite and spaced from each other, and an outer, tubular lens electrode arranged coaxially with said inner electrodes and in the space between said outwardly flaring end portions, whereby the opposite ends of said outer lens electrode are relatively widely spaced from the respective body portions of said inner electrodes, the danger of corona discharge from said opposite ends to the respective inner electrodes being substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
- An electrostatic lens arrangement comprising, in combination, a pair of tubular, axially aligned, inner electrodes, each of said electrodes having a body portion and an outwardly flaring end portion, said end portions being located opposite and spaced from each other, and an outer, tubular lens electrode arranged coaxially with said inner electrodes and located Within the space between and adjacent said outwardly flaring end portions of said inner electrodes, the opposite ends of said outer lens electrode being relatively widely spaced from the respective body portions of said inner electrodes, whereby the danger of corona discharge from the opposite ends of said outer lens electrode to the respective inner electrodes is substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
- An electrostatic lens arrangement comprising, in
- a pair of tubular, axially aligned, inner electrodes each of said electrodes having a body portion and an outwardly flaring end portion, said outwardly flaring end portions being located opposite and spaced from each other, an an outer, tubular lens electrode terminating in opposite edges and arranged coaxially with said inner electrodes and within the space between said outwardly flaring end portions, whereby the opposite edges of said outer lens electrode are relatively widely spaced from the respective body portions of said inner electrodes, the danger of corona discharge from said opposite edges to the respective inner electrodes being substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
- An electrostatic lens arrangement comprising, in
- said flaring end portions being conically shaped, and an outer, tubular lens electrode arranged coaxially with said inner electrodes and having a diameter greater than said outwardly flaring end portions of said inner electrodes, said outer lens electrode terminating in opposite ends and being located in the space between said outwardly flaring end portions of said inner electrodes, the opposite ends of said outer lens electrode 4 I a being relatively widely spaced from therespective body portions of said inner electrodes, the danger of corona discharge from said opposite ends to the respective inner electrodes being substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
- An electrostatic lens arrangement comprising, in combination, at least one tubular inner electrode having a body portion and an outwardly flaring end portion, and an outer, tubular lens electrode arranged coaxially with said inner electrode and located within the space between said outwardly flaring end portion and at leastthe outwardly flaring end portion itself, whereby the end of said outer lens electrode which is closest to said inner electrode is relatively widely spaced from the body portion of said inner electrode, and danger of corona discharge from said end of said outer lens electrode to said inner electrode, when said outer lens electrode is maintained at a potential which is substantially more negative than said inner electrode, is substantially lessened.
- An electrostatic lens arrangement comprising, in
- an outer, tubular lens electrode arranged coaxially with said inner electrode and enclosing the space between said outwardly flaring end portion and at least the outwardly flaring end portion itself, whereby the end of said outer lens electrode which is closest to said inner electrode is relatively widely spaced from the body portion of said inner electrode, and danger of corona discharge from said end of said outer lens electrode to said inner electrode, when said outer lens electrode is maintained at a potential which is substantially more negative than said inner electrode, is substantially lessened.
- An electrostatic lens arrangement comprising, in combination, a hollow cylindrical inner electrode having abody poition'and a flange-shaped outwardly flaring end portion, and an outer, tubular lens electrode arranged coaxially with said inner electrode and enclosing the space between said outwardly flaring end portion and at least the outwardly flaring end portion itself, whereby the end of said outer lens electrode which is closest to said inner electrode is relatively widely spaced from the body portion of said inner electrode, and danger of corona discharge from said end of said outer lens electrode to said inner electrode, when said outer lens electrode is maintained at a potential which is substantially more negative than said inner electrode, is substantially lessened.
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- Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
Description
Dec. 29, 1959' B. HENSEL STATIC ELECTRONIC LENS FOR ELECTRON BEAM VALVES Filed Feb. 16, 1954 United States Patent STATIC ELECTRONIC LENS FOR ELECTRON BEAM VALVES Bernhard Hensel, Berlin-Friedenau, Germany, assignor to Loewe Opta Aktiengesellschaft, Berlin-Steglitz, Germany, a company of Germany The familiar static electronic lenses for electron beam valves are usually shaped as follows:
Seen in the direction of the beam, the first anode behind the Wehnelt cylinder is followed by a tubular second anode; behind the latter is arranged, at a definite distance of one or several centimeters, another coaxial tube which is fed, as is the first one, with the high anode voltage (A -voltage). In the gap between these two anode tubes a third tube is arranged, the length of which corresponds approximately to the distance between the two anode tubes, and the diameter of which is several millimeters larger than that of the anode tubes. This intermediate tube .is either fed with a positive voltage which is in comparison much lower than the anode voltage or joined directly to the cathode. The intermediate electrode can be either just as long as the distance between the two anode tubes or a little longer or shorter.
In any case, in the familiar manner electric potential fields form at the transition points between the two anodes and the intermediate tube, andvconcentrate the electronic beam running through the tube axis.
If d is the diameter of the anode tubes and D the somewhat larger diameter of the intermediate tube, the desired electrostatic lens effect will be most perfectly achieved when the quotient d:D has a definite value. In the usual electrode systems this value amounts to about 0.7 to 0.9. For these reasons, the diameter d of the anode tubes is usually fixed at from to millimetersand the di-. ameter D of the intermediate electrode at from 12 to millimeters.
Now the inventor has noted, particularly when working at constructional development, that it is of advantage to combine the whole static electrode system described above in such a manner that instead of the single tubular electrodes being mounted, as hitherto, on glass or other insulating rods arranged parallel -to the tube axis, the whole system is designed as one integral member. a design will be accomplished the better the lighter .the individual static electrodes are, which were described above and which form the lens system. Contrary to this condition is the other condition, mentioned above, that the diameter d of the external anode tubes must not be smaller than a fixed value.
The present invention advantageously surmounts the difficulties which thus arise. Incontestable experiments have shown that to maintain the required ratio of d to D, it is only necessary to provide this diameter d at those points of the anode tubes which are directly at the origin of the lens fields, i.e. at the transition to the edges of the intermediate electrode. The diameter of the rest of the anode tubes, however, is unimportant for the production of the lens effect. On the basis of this knowledge and in accordance with the present invention, the anode tubes of an, in particular, tripartite static system of electronic lenses are provided with a much smaller diameter than hitherto, in particular with a diameter that can be substantially smaller than the diameter D of the tubular intermediate electrode. Only at those edges of the anode tubes facing the inside, in other words, at the point where the lens potential fields arise, the diameter d is so 'fixed that the desired value d:D=O.7 to 0.9 is still achieved. Accordingly, the anode tubes are provided with a funnel-shaped enlargement at the ends near the intermediate tube and have for the rest of their length only a relatively small diameter of a few millimeters. Thus a considerable saving in weight is achieved and the electronic lens can be designed so small and light that the single electrodes need not be fastened to individual mounting rods but can be combined without any constructional difficulties into one integral whole. The drawing shows one example of this invention, in a simplified arrangement of the three electrodes belonging to a static lens system of the common manner of operation: The tubular intermediate electrode .1 which is kept on a low voltage has a diameter D of a normal size of from 15 to 20 millimeters. edges of the two tubes 2 and 3, which are kept on a high 2 potential whereby, at the transition points 4 and 5 and in Such the familiar manner, the static fields which give rise to the lens elfect are formed. According to the invention, the tubes 2 and 3, which must, at the transition points 4 and 5, have a definite diameter d that must not be much smaller than the diameter D, are enlarged at 6 or 7 in a funnel shaped fashion, so that the exterior edge of the funnel attains the required diameter d. The rest of the anode tubes 2 and/or 3, however, has a much smaller diameter of e.g. only a few millimeters. This small diameterneed only be large enough to allow the beam, which has not yet been deflected at this point, to pass without touching the walls of the tubes 2 and 3.
Furthermore, it is often customary to provide the edges of the anode tubes at the transition points 4 and 5 with a calotte-shaped cover curved towards the interior of the tube and provided, as a perforated diaphragm, with a central aperture. This method, too, can in principle be realized, in connection with the presentinvention, by providing, e.g. at that spot of each anode tube at which the conical enlargement 6 or 7 begins, a perforated diaphragm 8 or 9. The cathode 11 and an electrode Wehnelt 12 are mounted in .the usual manner on a glass base 10. The first anode 13 .is arranged betweensaid electrode Wehnelt and the cylindrical electrode 3. A low tension voltage source L.T. is provided between said cathode 11 and said first anode 1-3, and-a high tension voltage source HT. is connected with its negative pole to the positive pole of the LT. voltage source and with its positive pole to 'said high tension electrodes 2 and 3.
What I claim is:
, 1. An electrostatic lens arrangement comprising, in combination, a pair of tubular, axially aligned, inner electrodes, each of said electrodes having a body portion and an outwardly flaring end portion, said end portions being located opposite and spaced from each other; and an outer, tubular lens electrode arranged coaxially with said inner electrodes and enclosing the space between said outwardly flaring end portions and at least said outwardly flaring end portions themselves, whereby the opposite ends of said outer lens electrode are relatively widely spaced from the respective body portions of said inner electrodes, and the danger of corona discharge from said opposite ends to the respective inner electrodes when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes is substantially lessened.
2. An electrostatic lens arrangement comprising, in combination, a pair of tubular, axially aligned, inner electrodes, each of said electrodes having a body portion and an outlwardly flaring end portion, said end portions being Opposite its external edges are the located opposite and spaced from each other, and an outer, tubular lens electrode arranged coaxially with said inner electrodes and in the space between said outwardly flaring end portions, whereby the opposite ends of said outer lens electrode are relatively widely spaced from the respective body portions of said inner electrodes, the danger of corona discharge from said opposite ends to the respective inner electrodes being substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
3. An electrostatic lens arrangement comprising, in combination, a pair of tubular, axially aligned, inner electrodes, each of said electrodes having a body portion and an outwardly flaring end portion, said end portions being located opposite and spaced from each other, and an outer, tubular lens electrode arranged coaxially with said inner electrodes and located Within the space between and adjacent said outwardly flaring end portions of said inner electrodes, the opposite ends of said outer lens electrode being relatively widely spaced from the respective body portions of said inner electrodes, whereby the danger of corona discharge from the opposite ends of said outer lens electrode to the respective inner electrodes is substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
4. An electrostatic lens arrangement comprising, in
combination, a pair of tubular, axially aligned, inner electrodes, each of said electrodes having a body portion and an outwardly flaring end portion, said outwardly flaring end portions being located opposite and spaced from each other, an an outer, tubular lens electrode terminating in opposite edges and arranged coaxially with said inner electrodes and within the space between said outwardly flaring end portions, whereby the opposite edges of said outer lens electrode are relatively widely spaced from the respective body portions of said inner electrodes, the danger of corona discharge from said opposite edges to the respective inner electrodes being substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
5. An electrostatic lens arrangement comprising, in
at least one of said flaring end portions being conically shaped, and an outer, tubular lens electrode arranged coaxially with said inner electrodes and having a diameter greater than said outwardly flaring end portions of said inner electrodes, said outer lens electrode terminating in opposite ends and being located in the space between said outwardly flaring end portions of said inner electrodes, the opposite ends of said outer lens electrode 4 I a being relatively widely spaced from therespective body portions of said inner electrodes, the danger of corona discharge from said opposite ends to the respective inner electrodes being substantially lessened when said outer lens electrode is maintained at a potential which is substantially more negative than that of said inner electrodes.
6. An electrostatic lens arrangement comprising, in combination, at least one tubular inner electrode having a body portion and an outwardly flaring end portion, and an outer, tubular lens electrode arranged coaxially with said inner electrode and located within the space between said outwardly flaring end portion and at leastthe outwardly flaring end portion itself, whereby the end of said outer lens electrode which is closest to said inner electrode is relatively widely spaced from the body portion of said inner electrode, and danger of corona discharge from said end of said outer lens electrode to said inner electrode, when said outer lens electrode is maintained at a potential which is substantially more negative than said inner electrode, is substantially lessened.
7. An electrostatic lens arrangement comprising, in
combination, a hollow cylindrical inner electrode having 1,
a body portion and a conically shaped outwardly flaring end portion, an an outer, tubular lens electrode arranged coaxially with said inner electrode and enclosing the space between said outwardly flaring end portion and at least the outwardly flaring end portion itself, whereby the end of said outer lens electrode which is closest to said inner electrode is relatively widely spaced from the body portion of said inner electrode, and danger of corona discharge from said end of said outer lens electrode to said inner electrode, when said outer lens electrode is maintained at a potential which is substantially more negative than said inner electrode, is substantially lessened.
I 8. An electrostatic lens arrangement comprising, in combination, a hollow cylindrical inner electrode having abody poition'and a flange-shaped outwardly flaring end portion, and an outer, tubular lens electrode arranged coaxially with said inner electrode and enclosing the space between said outwardly flaring end portion and at least the outwardly flaring end portion itself, whereby the end of said outer lens electrode which is closest to said inner electrode is relatively widely spaced from the body portion of said inner electrode, and danger of corona discharge from said end of said outer lens electrode to said inner electrode, when said outer lens electrode is maintained at a potential which is substantially more negative than said inner electrode, is substantially lessened.
References Cited in the file of this patent UNITED STATES PATENTS 2,219,405 Sukumlyn Oct. 29, 1940 2,226,107 Schlesinger Dec. 24, 1940 2,405,611 Samuel Aug. 13, 1946 2,476,060 Moss July 12, 1949
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE747387X | 1953-02-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2919378A true US2919378A (en) | 1959-12-29 |
Family
ID=6648615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US410619A Expired - Lifetime US2919378A (en) | 1953-02-18 | 1954-02-16 | Static electronic lens for electron beam valves |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2919378A (en) |
| GB (1) | GB747387A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2142436A1 (en) * | 1970-09-04 | 1972-03-09 | Philips Nv | TV camera tubes and provided with one of the like television camera tubes before direction |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2219405A (en) * | 1938-08-20 | 1940-10-29 | Thomas W Sukumlyn | Electromagnetic lens |
| US2226107A (en) * | 1933-12-09 | 1940-12-24 | Loewe Radio Inc | Braun tube, more particularly for television purposes |
| US2405611A (en) * | 1942-06-26 | 1946-08-13 | Bell Telephone Labor Inc | Electron beam amplifier |
| US2476060A (en) * | 1945-01-11 | 1949-07-12 | Cossor Ltd A C | Electron gun structure |
-
1954
- 1954-02-16 US US410619A patent/US2919378A/en not_active Expired - Lifetime
- 1954-02-17 GB GB4651/54A patent/GB747387A/en not_active Expired
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2226107A (en) * | 1933-12-09 | 1940-12-24 | Loewe Radio Inc | Braun tube, more particularly for television purposes |
| US2219405A (en) * | 1938-08-20 | 1940-10-29 | Thomas W Sukumlyn | Electromagnetic lens |
| US2405611A (en) * | 1942-06-26 | 1946-08-13 | Bell Telephone Labor Inc | Electron beam amplifier |
| US2476060A (en) * | 1945-01-11 | 1949-07-12 | Cossor Ltd A C | Electron gun structure |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2142436A1 (en) * | 1970-09-04 | 1972-03-09 | Philips Nv | TV camera tubes and provided with one of the like television camera tubes before direction |
Also Published As
| Publication number | Publication date |
|---|---|
| GB747387A (en) | 1956-04-04 |
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