US2483457A - Cathode-ray tube - Google Patents
Cathode-ray tube Download PDFInfo
- Publication number
- US2483457A US2483457A US586740A US58674045A US2483457A US 2483457 A US2483457 A US 2483457A US 586740 A US586740 A US 586740A US 58674045 A US58674045 A US 58674045A US 2483457 A US2483457 A US 2483457A
- Authority
- US
- United States
- Prior art keywords
- cathode
- screen
- tube
- potential
- ray
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000011248 coating agent Substances 0.000 description 13
- 238000000576 coating method Methods 0.000 description 13
- 239000000463 material Substances 0.000 description 7
- 239000004020 conductor Substances 0.000 description 5
- 230000007423 decrease Effects 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 201000009310 astigmatism Diseases 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000005686 electrostatic field Effects 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
Images
Classifications
-
- 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
- H01J29/80—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching
Definitions
- This invention relates to a cathode-ray tube that .is provided with a plurality of 'spaced 4coaxial conducting rings to which successively higher ⁇ potentials are to be applied in steps :increasing toward the outer end of the tube.
- the portion 'of the tube .to which the rings are applied is cylindrical'ly 'shaped and has lan 'approximately flat outer circular end.
- This tube is of the sort in which a cathode-ray or :beam is produced by an electron gun having a control electrode.
- the beam strikes a luminescent screen and produces a spot or trace of light of which the brilliance varies in accordance with .the screen material, the beam accelerating potential and the beam current.
- Bright spots or traces can be ,produced on 'the screen by using high .current or high voltage, or both, for the beam.
- high current when high current is used the beam diameter 'or size of this spot. or trace on the screen is increased,causingdecrease of resolution of the picture. lOn the contrary,
- the acceleration of the beam can be increased without decreasing the deflection sensitivity proportionally. But heretofore when accelerating potentials have been applied to cathode-ray beams after deection thereof, distortion of the pattern traced by the beam on the 'screen and decrease of the amount of screen area that vwas utilized have resulted inthe cases VWhere the inftensiiier potential was considerably more than twice that of the second lanode potential.
- accelerating potential can be applied to a cathode-ray beam without serious distortion after the beam has been deected even when such potential is up to about ten times that of the second wanode potential.
- reference character I indicates a glass cathode-ray tube which comprises a neck 2 and body portion 3 which are cylindrical.
- the cathode-ray beam generating, accelerating and focussing electrodes of a known sort are diagrammatically indicated by reference character 4.
- the horizontal and vertical deflection plates are indicated at 5 and 6. The way to generate and deflect the beam so that the end thereof will traverse the inner face of the tube is old and well known.
- a plurality of annular surfaces or rings 8, 9, l0 and Il of conducting material such as platinum or graphite with spaces between adjacent rings is applied to the inside wall of the cylindrical body portion 3 of the tube.
- the ring 8 may be wide enough t0 extend some distance into the neck 2 of the tube.
- the cylindrical shape of this portion 3 enables the beam to be kept at a maximum distance from the edges of electrostatic fields where distortions of the cathode-ray beam would otherwise occur.
- These rings 8, 9, I and I! are maintained at successively higher potentials in any desirable way.
- these rings may be connected by terminals I2, I3, I4 and I5 to successively higher potentials from sources, not shown, which provide the lowest potential at terminal I2 and the highest at terminal I5, ranging by equal steps from say 10,000 volts to 30,000 volts.
- the large cylindrical portion 3 of the tube I may be coated on the inside with a thin layer I6 of material of high resistance indicated by dots, with potentials applied only to terminals I2 and I5, the potential applied at terminal I being suiliciently higher than that applied to terminal I2 to provide the desired difference of potential.
- a screen or layer or" luminescent material 20 is applied to the inside surface of the large end of the tube I.
- An electrically conducting coating or layer 2l of material such as a coating of chromium thin enough to be substantially transparent may be applied to the inside surface of the face of the tube I before the luminescent material 20 is applied.
- a 10 to 1 ratio of postaccelerating potential of the cathode-ray beam after the electrons leave the high potential anode indicated at 4' may be used without substantially reducing the useful screen area and with little, if any, distortion of the luminous spot which the beam makes on the screen 20. Also, with a 10 to 1 ratio there is only slight reduction of useful screen area, and this useful screen area remains circular instead of assuming a barrel-like shape.
- the spacing of these rings may be changed so that, for example, the spacing between the ring 8 and the ring 9 4 would be much larger, and the other spacings would be smaller. Such distribution of the rings results in further reduction of pattern and spot distortion.
- a cathode-ray tube having a neck and a cylindrical body portion of larger diameter than said neck, a series of spaced bands of conducting material on the inside of said cylindrical portion, a luminescent screen at the end of said cylindrical portion said screen being applied over a transparent conductive coating and a high resistance coating connecting said transparent coating to one of said bands of conducting material.
- a cathode-ray tube having a neck and a cylindrical body portion of larger diameter than said neck, a series of spaced bands of conducting material on the inside of said cylindrical portion, and a luminescent screen at the end of said cylindrical portion electrically connected to said band closest to it by a high resistance coating and a transparent conductive coating over which said luminescent screen has been applied.
- a cathode-ray tube having a neck and a cylindrical body portion of larger diameter than said neck, a series of spaced bands of conducting material on the inside of said cylindrical portion and a luminescent screen at the end of said cylindrical portion connected to the band of conducing material closest to it by a high resistance metallic coating and a transparent conductive coating over which said screen has been applied.
Landscapes
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
Description
@ci 4 i949- R. FELD? ETAL y 2,433,457
'cATHoDE-RAY TUBE Filed April 5, 1945 #5w-'J7 MWI/WENTORJ' BY y HTTONEY Patented Oct. 4, 1**949 UNITED STATES ENT OFFI CE.
vCATHODE-RAY TUBE Application April 5, 1945, Serial N0. 585,740
3 Claims.
This invention relates to a cathode-ray tube that .is provided with a plurality of 'spaced 4coaxial conducting rings to which successively higher `potentials are to be applied in steps :increasing toward the outer end of the tube. The portion 'of the tube .to which the rings are applied is cylindrical'ly 'shaped and has lan 'approximately flat outer circular end.
This tube is of the sort in which a cathode-ray or :beam is produced by an electron gun having a control electrode. The beam is focussed electrostatcally by a focussing yelectrode and is :deflected electrostaticallyby deflectione'lectrodes which deect the beam in 'a known =way.. The beam strikes a luminescent screen and produces a spot or trace of light of which the brilliance varies in accordance with .the screen material, the beam accelerating potential and the beam current.
It is known that with cathode-ray tubes of this character -high accelerating voltages `are needed in order to obtain a highly `bright spot or trace v:on the screen material. Such spots or traces :on 'the screen of a cathode-ray tube face 'are desirable 'or even necessary:
(a) When high speed transients are to be observed or recorded.
(b) When an optical projection of an 'image is to be made upon a screen as in -oscillog-raphy or with television projection.
Bright spots or traces can be ,produced on 'the screen by using high .current or high voltage, or both, for the beam. However, when high current is used the beam diameter 'or size of this spot. or trace on the screen is increased,causingdecrease of resolution of the picture. lOn the contrary,
high voltage decreases the beam diameter so that the size of the spot or trace is decreased.
Troubles arise with high voltages, such as insulation diiculties, low sensitivity of deection of the beam, distortion of the pattern on the screen due to high ratio oi intensifier potential to second anode potential, and spot distortion or astigmatism due to unsymmetrical field distribution.
It has also been found that with cathode-ray tubes so shaped that their diameters increase gradually towards their screens, serious distortion of the spot on the screen and serious distortion of the patterns occur When ratios of more than about two to one are used.
It is well known that the amount of deection of the beam decreases with increase of accelerating potential when the accelerating voltage is applied to the beam of electrons before the beam is deected. However, by applying some of the accelerating potential after deflecting the beam,
the acceleration of the beam can be increased without decreasing the deflection sensitivity proportionally. But heretofore when accelerating potentials have been applied to cathode-ray beams after deection thereof, distortion of the pattern traced by the beam on the 'screen and decrease of the amount of screen area that vwas utilized have resulted inthe cases VWhere the inftensiiier potential was considerably more than twice that of the second lanode potential.
Troubles which have heretofore limited the ratio of intensifier vpotential to second anode potential in cathode-ray tubes, but are overcome by the vpresent invention, are: voltage breakdown between electrodes is avoided; haphazard electrical 'charges on the glass walls of such tubes are prevented, thus avoiding axial dissy-mmetry and permitting operation at higher potentials; nonuniformity of screen potential and potentials at other points on 'the inside of the tube bulb caused by tube mountings and other objects that come into contact with the outside tube which have occurred when high post-accelerating potentials were applied to the beams with deection plates at ground potential are improved. Also, distortion of the pattern on the screen is avoided or greatly improved and much better vfocussing of the beam is obtained.
By the Ypresent invention accelerating potential can be applied to a cathode-ray beam without serious distortion after the beam has been deected even when such potential is up to about ten times that of the second wanode potential.
The invention may be understood from the description in connection with the accompanying drawing which is 'a somewhat diagrammatic side View of an illustrative embodiment of the invention.
In the drawing, reference character I indicates a glass cathode-ray tube which comprises a neck 2 and body portion 3 which are cylindrical. The cathode-ray beam generating, accelerating and focussing electrodes of a known sort are diagrammatically indicated by reference character 4. The horizontal and vertical deflection plates are indicated at 5 and 6. The way to generate and deflect the beam so that the end thereof will traverse the inner face of the tube is old and well known.
A plurality of annular surfaces or rings 8, 9, l0 and Il of conducting material such as platinum or graphite with spaces between adjacent rings is applied to the inside wall of the cylindrical body portion 3 of the tube. The ring 8 may be wide enough t0 extend some distance into the neck 2 of the tube. The cylindrical shape of this portion 3 enables the beam to be kept at a maximum distance from the edges of electrostatic fields where distortions of the cathode-ray beam would otherwise occur. These rings 8, 9, I and I! are maintained at successively higher potentials in any desirable way. For example, these rings may be connected by terminals I2, I3, I4 and I5 to successively higher potentials from sources, not shown, which provide the lowest potential at terminal I2 and the highest at terminal I5, ranging by equal steps from say 10,000 volts to 30,000 volts. The large cylindrical portion 3 of the tube I may be coated on the inside with a thin layer I6 of material of high resistance indicated by dots, with potentials applied only to terminals I2 and I5, the potential applied at terminal I being suiliciently higher than that applied to terminal I2 to provide the desired difference of potential.
When such a resistive coating is used, electrical charges are prevented from accumulating on the wall of the tube between conducting areas 8, 9, I0 and II and no arcing occurs between these areas even when a Very high dilerence of potential is applied between areas 8 and Il. Also, no external connections are necessary for the areas 9 and I0 when the resistance coating is used, and stray emission of electrical Charges does not take place or is greatly reduced.
A screen or layer or" luminescent material 20 is applied to the inside surface of the large end of the tube I. An electrically conducting coating or layer 2l of material such as a coating of chromium thin enough to be substantially transparent may be applied to the inside surface of the face of the tube I before the luminescent material 20 is applied. This coating together with the coating I6 and the conducting rings 8, 9, IB and I I, form a complete internal electric shield ior the tube, thus avoiding interference with the functioning of the tube by external electric elds, and definitely fixing the potential distribution which determines the tube performance.
With this invention a 10 to 1 ratio of postaccelerating potential of the cathode-ray beam after the electrons leave the high potential anode indicated at 4' may be used without substantially reducing the useful screen area and with little, if any, distortion of the luminous spot which the beam makes on the screen 20. Also, with a 10 to 1 ratio there is only slight reduction of useful screen area, and this useful screen area remains circular instead of assuming a barrel-like shape.
Instead of the rings 8, 9, I 0 and II shown on the drawings being equally spaced, the spacing of these rings may be changed so that, for example, the spacing between the ring 8 and the ring 9 4 would be much larger, and the other spacings would be smaller. Such distribution of the rings results in further reduction of pattern and spot distortion.
What is claimed is:
1. A cathode-ray tube having a neck and a cylindrical body portion of larger diameter than said neck, a series of spaced bands of conducting material on the inside of said cylindrical portion, a luminescent screen at the end of said cylindrical portion said screen being applied over a transparent conductive coating and a high resistance coating connecting said transparent coating to one of said bands of conducting material.
2. A cathode-ray tube having a neck and a cylindrical body portion of larger diameter than said neck, a series of spaced bands of conducting material on the inside of said cylindrical portion, and a luminescent screen at the end of said cylindrical portion electrically connected to said band closest to it by a high resistance coating and a transparent conductive coating over which said luminescent screen has been applied.
3. A cathode-ray tube having a neck and a cylindrical body portion of larger diameter than said neck, a series of spaced bands of conducting material on the inside of said cylindrical portion and a luminescent screen at the end of said cylindrical portion connected to the band of conducing material closest to it by a high resistance metallic coating and a transparent conductive coating over which said screen has been applied.
RUDOLF FELDT. IRVING EDlVIUND LEMPERT.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 2,123,636 Schwartz July 12, 1938 2,181,563 Knoll Sept. 27, 1938 2,266,773 Law Dec. 23, 1941 2,269,115 Koch Jan. 6, 1942 2,278,478 Oliver Apr. '7, 1942 2,297,752 Du Mont Oct. 6, 1942 2,404,046 Flory et al. July 16, 1946 2,409,514 Pratt Oct. 15, 1946 2,413,276 Woli Dec. 24, 1946 FOREIGN PATENTS Number Country Date 441,693 Great Britain Jan. 20, 1936 549,278 Great Britain Nov. 13, 1942
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR926000D FR926000A (en) | 1945-04-05 | ||
US586740A US2483457A (en) | 1945-04-05 | 1945-04-05 | Cathode-ray tube |
GB13197/46A GB615563A (en) | 1945-04-05 | 1946-05-01 | Improvements in cathode-ray tube |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US586740A US2483457A (en) | 1945-04-05 | 1945-04-05 | Cathode-ray tube |
Publications (1)
Publication Number | Publication Date |
---|---|
US2483457A true US2483457A (en) | 1949-10-04 |
Family
ID=24346948
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US586740A Expired - Lifetime US2483457A (en) | 1945-04-05 | 1945-04-05 | Cathode-ray tube |
Country Status (3)
Country | Link |
---|---|
US (1) | US2483457A (en) |
FR (1) | FR926000A (en) |
GB (1) | GB615563A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2580250A (en) * | 1950-07-29 | 1951-12-25 | Gen Electric | Cathode-ray type of electron discharge device |
US2631254A (en) * | 1951-12-26 | 1953-03-10 | Allied Electric Products Inc | Geometrically coated cathode-ray tube |
US2937314A (en) * | 1959-12-28 | 1960-05-17 | Columbia Broadcasting Syst Inc | High resolution cathode ray tube apparatus |
US3959686A (en) * | 1975-01-06 | 1976-05-25 | Gte Sylvania Incorporated | Cathode ray tube construction having defined processing and operational means incorporated therein |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3274416A (en) * | 1961-09-27 | 1966-09-20 | Alexander A Rotow | Image intensifier type camera tube with potential field correcting means |
US3240973A (en) * | 1962-03-01 | 1966-03-15 | Rca Corp | Electrostatic saddle field collimating system |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB441693A (en) * | 1933-07-31 | 1936-01-20 | Telefunken Gmbh | Improvements in or relating to cathode ray tubes and methods and apparatus for making the same |
US2123636A (en) * | 1932-02-23 | 1938-07-12 | Firm Fernseh Aktien Ges | High-vacuum cathode ray tube |
US2131563A (en) * | 1933-08-01 | 1938-09-27 | Telefunken Gmbh | Cathode ray tube |
US2266773A (en) * | 1937-05-11 | 1941-12-23 | Rca Corp | Electron device |
US2269115A (en) * | 1940-11-12 | 1942-01-06 | Du Mont Allen B Lab Inc | Cathode-ray tube |
US2278478A (en) * | 1941-01-10 | 1942-04-07 | Bell Telephone Labor Inc | Magnetic coil and arrangement utilizing the same |
US2297752A (en) * | 1939-07-10 | 1942-10-06 | Du Mont Allen B Lab Inc | Monitoring and control system |
GB549278A (en) * | 1940-08-28 | 1942-11-13 | Philips Nv | Improvements in or relating to cathode-ray tubes of the wall coated type |
US2404046A (en) * | 1941-06-21 | 1946-07-16 | Rca Corp | Television transmitting apparatus |
US2409514A (en) * | 1945-01-30 | 1946-10-15 | Rca Corp | Cathode-ray tube |
US2413276A (en) * | 1942-11-19 | 1946-12-24 | Rca Corp | Cathode-ray apparatus |
-
0
- FR FR926000D patent/FR926000A/fr not_active Expired
-
1945
- 1945-04-05 US US586740A patent/US2483457A/en not_active Expired - Lifetime
-
1946
- 1946-05-01 GB GB13197/46A patent/GB615563A/en not_active Expired
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2123636A (en) * | 1932-02-23 | 1938-07-12 | Firm Fernseh Aktien Ges | High-vacuum cathode ray tube |
GB441693A (en) * | 1933-07-31 | 1936-01-20 | Telefunken Gmbh | Improvements in or relating to cathode ray tubes and methods and apparatus for making the same |
US2131563A (en) * | 1933-08-01 | 1938-09-27 | Telefunken Gmbh | Cathode ray tube |
US2266773A (en) * | 1937-05-11 | 1941-12-23 | Rca Corp | Electron device |
US2297752A (en) * | 1939-07-10 | 1942-10-06 | Du Mont Allen B Lab Inc | Monitoring and control system |
GB549278A (en) * | 1940-08-28 | 1942-11-13 | Philips Nv | Improvements in or relating to cathode-ray tubes of the wall coated type |
US2269115A (en) * | 1940-11-12 | 1942-01-06 | Du Mont Allen B Lab Inc | Cathode-ray tube |
US2278478A (en) * | 1941-01-10 | 1942-04-07 | Bell Telephone Labor Inc | Magnetic coil and arrangement utilizing the same |
US2404046A (en) * | 1941-06-21 | 1946-07-16 | Rca Corp | Television transmitting apparatus |
US2413276A (en) * | 1942-11-19 | 1946-12-24 | Rca Corp | Cathode-ray apparatus |
US2409514A (en) * | 1945-01-30 | 1946-10-15 | Rca Corp | Cathode-ray tube |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2580250A (en) * | 1950-07-29 | 1951-12-25 | Gen Electric | Cathode-ray type of electron discharge device |
US2631254A (en) * | 1951-12-26 | 1953-03-10 | Allied Electric Products Inc | Geometrically coated cathode-ray tube |
US2937314A (en) * | 1959-12-28 | 1960-05-17 | Columbia Broadcasting Syst Inc | High resolution cathode ray tube apparatus |
US3959686A (en) * | 1975-01-06 | 1976-05-25 | Gte Sylvania Incorporated | Cathode ray tube construction having defined processing and operational means incorporated therein |
Also Published As
Publication number | Publication date |
---|---|
FR926000A (en) | 1947-09-30 |
GB615563A (en) | 1949-01-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3143681A (en) | Spiral electrostatic electron lens | |
US2690517A (en) | Plural beam electron gun | |
GB721460A (en) | Voltage indicating valve | |
US2483457A (en) | Cathode-ray tube | |
US3185879A (en) | Cathode ray tube having deflection enhancement means | |
Schlesinger | Progress in the development of post-acceleration and electrostatic deflection | |
US3731136A (en) | Cylindrical electrode system for focusing and deflecting an electron beam | |
US3102212A (en) | Cathode ray tube with low velocity deflection and post deflection beam acceleration | |
US3921025A (en) | Dual-beam CRT with vertical trace bowing correction means | |
US3696261A (en) | Cathode ray tube with plural beams for each color element | |
US2267083A (en) | Arrangement comprising cathode ray tubes | |
GB1078832A (en) | Electrostatic electron optical system | |
US2523406A (en) | Insulated anode for cathode-ray tubes | |
US2911563A (en) | Electrostatic lens and deflection system | |
US2726348A (en) | Multiple beam gun | |
US2131563A (en) | Cathode ray tube | |
US2189320A (en) | Electro-optical device | |
US3024380A (en) | Cathode ray tube gun construction | |
US2176974A (en) | Cathode ray tube | |
US3133220A (en) | Post deflection accelerated tube | |
US2898491A (en) | Cathode ray tubes | |
US3249784A (en) | Direct-view signal-storage tube with image expansion means between storage grid and viewing screen | |
US2021253A (en) | Kinescope | |
US3694686A (en) | Unidirectional double deflection type cathode ray tube | |
US3240973A (en) | Electrostatic saddle field collimating system |