US2178232A - Cathode ray tube - Google Patents
Cathode ray tube Download PDFInfo
- Publication number
- US2178232A US2178232A US133899A US13389937A US2178232A US 2178232 A US2178232 A US 2178232A US 133899 A US133899 A US 133899A US 13389937 A US13389937 A US 13389937A US 2178232 A US2178232 A US 2178232A
- Authority
- US
- United States
- Prior art keywords
- particles
- mosaic
- electrode
- cathode ray
- mica
- 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
- 239000002245 particle Substances 0.000 description 69
- 239000010445 mica Substances 0.000 description 25
- 229910052618 mica group Inorganic materials 0.000 description 25
- 229910001610 cryolite Inorganic materials 0.000 description 19
- 239000002585 base Substances 0.000 description 16
- 239000010408 film Substances 0.000 description 15
- 230000003287 optical effect Effects 0.000 description 15
- 206010034972 Photosensitivity reaction Diseases 0.000 description 14
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 14
- 239000004020 conductor Substances 0.000 description 14
- 229910052709 silver Inorganic materials 0.000 description 14
- 239000004332 silver Substances 0.000 description 14
- 229910052792 caesium Inorganic materials 0.000 description 11
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 11
- 238000000151 deposition Methods 0.000 description 10
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 230000036211 photosensitivity Effects 0.000 description 8
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 7
- 238000000576 coating method Methods 0.000 description 7
- 229910000510 noble metal Inorganic materials 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 229910052783 alkali metal Inorganic materials 0.000 description 4
- 150000001340 alkali metals Chemical class 0.000 description 4
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 4
- 229910001634 calcium fluoride Inorganic materials 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- 230000001235 sensitizing effect Effects 0.000 description 4
- NDVLTYZPCACLMA-UHFFFAOYSA-N silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 description 4
- 235000013024 sodium fluoride Nutrition 0.000 description 4
- 239000011775 sodium fluoride Substances 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 239000011810 insulating material Substances 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- -1 cryolite Chemical compound 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 150000002736 metal compounds Chemical class 0.000 description 2
- 239000013528 metallic particle Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 230000002165 photosensitisation Effects 0.000 description 2
- 239000003504 photosensitizing agent Substances 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 229910001923 silver oxide Inorganic materials 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- ZVNPWFOVUDMGRP-UHFFFAOYSA-N 4-methylaminophenol sulfate Chemical compound OS(O)(=O)=O.CNC1=CC=C(O)C=C1.CNC1=CC=C(O)C=C1 ZVNPWFOVUDMGRP-UHFFFAOYSA-N 0.000 description 1
- 206010034960 Photophobia Diseases 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000012799 electrically-conductive coating Substances 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 208000013469 light sensitivity Diseases 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 208000017983 photosensitivity disease Diseases 0.000 description 1
- 231100000434 photosensitization Toxicity 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000003362 replicative effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000000126 substance Substances 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
- H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
- H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
- H01J29/36—Photoelectric screens; Charge-storage screens
- H01J29/39—Charge-storage screens
- H01J29/43—Charge-storage screens using photo-emissive mosaic, e.g. for orthicon, for iconoscope
Definitions
- the principal object 'of my invention is to provide an improved cathode raytube having a mosaic type target electrode of greater photol sensitivity than a conventional electrode having the same surface leakage.
- a further object is to provide an improved and highly sensitized electrode having greater photosensitivity than has heretofore been attainable.
- the target4 electrode or screen is so made that the insulating surface betweenv individual photosensitized elements is of considerably greater extent and the paths between them of higher resistance than I in the conventional mosaic electrode.
- an intermediate insulating coating or layer of crystals, having a flaky amorphous texture is interposed between the layer of. mosaic particles and an insulating base, such as mica, thereb-y increasing the length and resistance of the electrical paths from particle to particle.
- the individual mosaic particles are formed on the intermediate insulating layer, oxidized, and photosensitized with caesium or other light sensitive materials during the evacuation of the tube.
- the photosensitivity of the particles may then be raised to a much greatervalue than heretofore obtainable by evaporating an exceedingly thin and preferably discontinuous film of metal, suchfas nickel, or preferablyv of a noble metal, such as silver, to coat the light sensitive particles with metal.
- Figure 1 is a diagrammatic view illustrating one form of a television device for incorporating my invention.
- Figure 2 is an enlarged fragmentary sectional View of the photosensitive mosaic screen shown in Figure 1.
- the tube comprises a highly evacuated glass envelope or bulb l with a tubular arm or neck section enclosing a conventional type electron gun and a spherical section enclosing a flat target or mosaic electrode 2 so positioned that its front surface may be scanned by a beam of electrons from the electron gun and also may have projected upon it the optical image to be transmitted. Since the imageis produced from an object situated outside the tube, that portion or window 3 of the spherical section -opposite the electrode 2 is made optically uniform so that the image to be transmitted may be projected upon the electrode with a minimum of distortion by the lens system 4.
- the electron gun assembly is of the conventional type, and comprises a ⁇ cathode 5 from which an electron rstream may be drawn, a control electrode 5 connected to the usual biasing battery, and a first anode 'l maintained positive with respect to the cathode 5 by a battery 8.
- the electron stream leaving the iirst anode l is accelerated and concentratedl into an electron scanning beam focused on the front surface of the target 2 by a second anode 9, which is preferably a conductive coating on the surface of the envelope I near the neck of the bulb but removed from that portion through which is projected the optical image to'be transmitted.
- Conventional deflection means such as deflection coils lil and Il may be used to sweep the beam in a horizontal and vertical plane, respectively, to scan the target. It is obvious that conventional electrostatic deection plates may be substituted for one or both of the deflection coils if desired.
- the electrode 2 is connected through the impedance I2 to ground and to the collector electrode or second anode 9, and in operation the current flow in this circuit produces a voltage drop across the impedance I2 which may be impressed on the input of a translating device I3, further amplified and applied to a transmitting network in a manner well known to the art.
- an insulating foundation sheet or base I4 such as a sheet of mica is coated with metal or other electrically conducting material, such as a film of platinum which is coextensive with the base I4 and serves as a signal electrode from which the picture signals may be obtained. The other side of.
- the sheet of mica has on its surface an insulating layer or film of a fluoride, such as cryolite, calcium fluoride, or sodium fluoride, on which the photosensitive mosaic surface which is scanned by the electron beam and on which the optical image to be transmitted is focused is formed.
- a fluoride such as cryolite, calcium fluoride, or sodium fluoride
- the mosaic surface is in capacitive relationship with the signal electrode.
- I provide on the mosaic surface a coating of silver or other metal, such as the noble metals, nickel or the like, which increases the light sensitivity of the mosaic surface.
- a thin sheet of insulating material I4 such as mica, having a plane surface and of uniform thickness is coated on one side with a thin continuous film I5 of electrically conducting material, such as platinum.
- the other side or front of the mica sheet I4 is then coated with a thin layer or film of insulation preferably by placing the mica sheet in a sealed glass envelope which may be evacuated.
- the coating of the mica with a film of insulation may most conveniently be done by mounting within the sealed envelope a tungsten filament which may be heated to incandescence and which has been coated with the fluoride or other insulating material with which the mica sheet is to be coated. rI'he envelope is then evacuated, and the filament heated to flash off enough of the material with which it is coated to produce the desired film.
- cryolite as a materialy with which to coat the mica
- the sheet of mica is removed from the evacuated envelope, and the deposited film of cryolite is dusted with a finely divided metal compound, such as silver oxide, and the dusted sheet is rapidly heated in an oven at 800 C. until the silver oxide is reduced to silver, of which individual and minute portions are drawn up by surface tension to form a multiplicity of microscopic particles I'I, spaced from each other, the number and average size of the particles in a unit area being sufficient to satisfy the operating requirements in the way of detail of picture reproduction.
- a finely divided metal compound such as silver oxide
- the mosaic surface may be formed however in a variety of ways in addition to the method described.
- a thin continuous film of silver may be deposited on the cryolite which is broken up into microscopic particles by suitable heat treatment.
- the mica sheet carrying the particles or individual elements on the intermediate layer or film of cryolite I6 is then mounted in the tube as shown in Figure l, the tube evacuated, and the silver particles oxidized and photosensitized by exposure to caesium Vapor in the usual way. Somewhat more caesium may be used than in sensitizing the conventional mosaic, and thereby greater photosensitivity obtained without a correspondingly greater surface leakage.
- the baking may be discontinued when the photosensitivity has passed the maximum and has decreased very slightly at which point the surface leakage is negligible, probably because the increased separatiori provided by the film of evaporated cryolite effectively isolates the particles. Following the photosensitizing process the tube is sealed off from the pump.
- the tube is connected, as shown in Figure l, an optical image of an object projected on the mosaic electrode 2, and the mosaic electrode scanned with the cathode ray beam in a manner well known in the art.
- the picture signals derived from the signal electrode I2 are amplified by a series of amplifiers, such as the amplifier I3, and the image projected on the mosaic 2 is recreated on a viewing tube (not shown).
- the resolution of the recreated image which may be defined as the ability to distinguish two lines of an image which are close together, is noted to determine the surface condition of the photosensitive particles.
- a noble metal such as silver
- the metal may be evaporated from a recess I9 in the wall of the tube I opposite the mosaic surface, but removed from the window through which the image of the object to be transmitted is projected.
- a tungsten lament 20 coated with silver or other metal to be evaporated is placed within this recess so that the metal projected from the filament coats the mosaic surface.
- a cathode ray television transmitting tube comprising an envelope having a transparent window for the transmission of an optical image, an electrode assembly including a non-conducting base in registry with said window, an intermediate thin lawer of overlapping crystals of an insulating material coextensive with and on one side of said base, a multiplicity of minute discrete photosensitive particles on said intermediate layer, a film of a noble metal on 'said particles and an electrically conducting material coextensive with and on said non-conducting base in capacitive relationship with said photosensitive particles.
- a cathode ray television transmitting tube comprising an envelope having a transparent window for the transmission of an optical image, an electrode assembly including a non-conducting base in registry with said window, an intermediate thin layer of Va material selected from the group consisting of cryolite, calcium fluoride, and sodium uoride coextensive with, and on one side of said base, a multiplicity of discrete photosensitive particles each of minute size on said intermediate layer, and an electrically conducting materialcoextensive with andon said nonconducting base and in capacitive relationship with said photosensitive particles.
- a lcathode ray television transmitting tube comprising an envelope having a transparent window for the transmission of an optical image, an electrode assembly including a non-conducting base in registry with said window, an intermediate thin layer of amaterial selected from the group consisting of cryolite, calcium iluoride, and sodium uride coextensive with and on one side of said base, a multiplicity of discrete photosensitive particles each of minute size on said intermediate layer, a iilm of a noble metal on said particles and an electrically conductive coating coextensive with and on the opposite side of said non-conducting base.
- a light sensitive mosaic electrode comprising a sheet of mica, an intermediate layer of a material selected from the group consisting of cryolite, calcium uoride, and sodium fluoride coeXtensive with and on one side of said mica, a mosaic of minute discrete photosensitive particles on said intermediate layer and an electrical conductor coextensive with said mosaic and in capacitive relationship with said photosensitive particles.
- a light sensitive mosaic electrode comprising a sheet of mica, an intermediate thin layer of cryolite coextensive with and on one side of.
- said mica a mosaic of minute discrete photosensitive particles on said intermediate layer, a lm of silver on said particles and an electrical conductor coextensive with said mosaic and on the opposite side of said mica sheet.
- a light sensitive mosaic electrode comprising an electrically non-conducting base, an intermediate thin insulating layer with a roughened surface coextensive with and supported by said base, a mosaic of minute discrete photosensitive particles on said intermediate layer, a film of silver on said particles and an electrical conductor co-extensive with and in capacitive relationship with said photosensitive particles.
- 'Ihe method of producing a cathode ray tube having a mosaic electrode of mutually separated photosensitive particles in an envelope which includes the steps of depositing a noble metal on the photosensitive particles after evacuation and sealing of the envelope, projecting an optical image on said mosaic electrode, scanning the electrode to produce picture signals representative of the optical image on said electrode, creating a picture replica of the optical image with the produced picture signals, determining the resolution of the picture replica, and limiting the ydeposit of the noble metal in accordance with the resolution of the picture replica.
- the method of preparing a photosensitive mosaic surface upon an insulating target electrode for use in a cathode ray tube having means for producing a cathode ray beam for scanning said electrode which comprises the steps of forming a multiplicity of discrete metallic particles on said electrode, oxidizing the particles, photoelectrically sensitizing said particles by depositing alkali metal thereon, removing the excess alkali metal from areas intermediate the particles, tracing the developed cathode ray beam across the photosensitive particles to determine the resolution produced by the particles, depositing conducting material upon the photosensitive particles simultaneously with the scanning operation until the resolution has been reduced to a fraction of its previous value thereby limiting the period of deposition of the conducting material in accordance with observations of the signals resulting from scanning and subsequently heating the electrode to further photosensitize said particles.
- the method of preparing a photosensitive mosaic surface on an insulating target electrode for use within a cathode ray tube incorporating means for developing and scanning a cathode ray beam which comprises the steps of depositing a continuous lm of conductive material upon the target electrode, heating the lm to form a multiplicity of electrically isolated particles, oxidizing the formed particles, photoelectrically sensitizing the formed particles by depositing an alkali metal thereon, removing excess alkali metal from areas intermediate the formed particles, projecting an optical image on said particles, tracing the developed cathode ray beam over the formed particles to produce electrical signals representative of the optical image, producing a replica of the optical image with said electrical signals, determining the resolution of said optical image replica, depositing additional conducting material upon the formed particles simultaneously with the scanning operation until the resolution of the optical image replica has been reduced to a fraction of its previous value thereby effectively limiting the period of deposition of the additional conducting material in accordance with observations of the signals resulting from scanning and subsequently heating the target electrode to further
Landscapes
- Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US133899A US2178232A (en) | 1937-03-30 | 1937-03-30 | Cathode ray tube |
GB2192/38A GB491292A (en) | 1937-03-30 | 1938-01-22 | Improvements in or relating to cathode ray television transmitter tubes |
FR835007D FR835007A (fr) | 1937-03-30 | 1938-03-09 | Perfectionnements aux tubes à rayon cathodique |
CH203272D CH203272A (de) | 1937-03-30 | 1938-03-28 | Elektrische Entladungsröhre zum Aussenden elektrisch zu übermittelnder Bilder und Verfahren zur Herstellung dieser Röhre. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US133899A US2178232A (en) | 1937-03-30 | 1937-03-30 | Cathode ray tube |
Publications (1)
Publication Number | Publication Date |
---|---|
US2178232A true US2178232A (en) | 1939-10-31 |
Family
ID=22460810
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US133899A Expired - Lifetime US2178232A (en) | 1937-03-30 | 1937-03-30 | Cathode ray tube |
Country Status (4)
Country | Link |
---|---|
US (1) | US2178232A (fr) |
CH (1) | CH203272A (fr) |
FR (1) | FR835007A (fr) |
GB (1) | GB491292A (fr) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2533387A (en) * | 1948-11-16 | 1950-12-12 | Nat Union Radio Corp | Method and apparatus for making dynodes |
US2700626A (en) * | 1949-12-09 | 1955-01-25 | Bell Telephone Labor Inc | Secondary electron emissive electrodes |
US3195971A (en) * | 1961-01-05 | 1965-07-20 | Sylvania Electric Prod | Process for removing electrically conductive coatings from ceramics |
-
1937
- 1937-03-30 US US133899A patent/US2178232A/en not_active Expired - Lifetime
-
1938
- 1938-01-22 GB GB2192/38A patent/GB491292A/en not_active Expired
- 1938-03-09 FR FR835007D patent/FR835007A/fr not_active Expired
- 1938-03-28 CH CH203272D patent/CH203272A/de unknown
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2533387A (en) * | 1948-11-16 | 1950-12-12 | Nat Union Radio Corp | Method and apparatus for making dynodes |
US2700626A (en) * | 1949-12-09 | 1955-01-25 | Bell Telephone Labor Inc | Secondary electron emissive electrodes |
US3195971A (en) * | 1961-01-05 | 1965-07-20 | Sylvania Electric Prod | Process for removing electrically conductive coatings from ceramics |
Also Published As
Publication number | Publication date |
---|---|
FR835007A (fr) | 1938-12-09 |
CH203272A (de) | 1939-02-28 |
GB491292A (en) | 1938-08-30 |
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