US3896328A - Dual mode crt screen - Google Patents
Dual mode crt screen Download PDFInfo
- Publication number
- US3896328A US3896328A US473987A US47398774A US3896328A US 3896328 A US3896328 A US 3896328A US 473987 A US473987 A US 473987A US 47398774 A US47398774 A US 47398774A US 3896328 A US3896328 A US 3896328A
- Authority
- US
- United States
- Prior art keywords
- screen
- phosphor
- cathode ray
- persistence
- dual
- 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
- 230000009977 dual effect Effects 0.000 title claims abstract description 19
- 239000000463 material Substances 0.000 claims abstract description 33
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 22
- 230000002688 persistence Effects 0.000 claims description 17
- 230000005684 electric field Effects 0.000 claims description 5
- 230000005284 excitation Effects 0.000 claims description 4
- 230000003287 optical effect Effects 0.000 claims description 4
- 238000001429 visible spectrum Methods 0.000 claims description 4
- WUPHOULIZUERAE-UHFFFAOYSA-N 3-(oxolan-2-yl)propanoic acid Chemical compound OC(=O)CCC1CCCO1 WUPHOULIZUERAE-UHFFFAOYSA-N 0.000 claims description 3
- 229910052980 cadmium sulfide Inorganic materials 0.000 claims description 3
- 230000001747 exhibiting effect Effects 0.000 claims description 3
- 230000008859 change Effects 0.000 abstract description 2
- 239000005083 Zinc sulfide Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 230000002085 persistent effect Effects 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- 229910052984 zinc sulfide Inorganic materials 0.000 description 2
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 2
- 101100264195 Caenorhabditis elegans app-1 gene Proteins 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 229940047127 fiore Drugs 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B33/00—Electroluminescent light sources
- H05B33/12—Light sources with substantially two-dimensional radiating surfaces
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J31/00—Cathode ray tubes; Electron beam tubes
- H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
- H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
- H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
- H01J31/122—Direct viewing storage tubes without storage grid
Landscapes
- Luminescent Compositions (AREA)
- Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
Abstract
A dual phosphor screen is deposited on the inside surface of the faceplate of a CRT. A photo electroluminescent panel made up of a layer of photoconductive material and a layer of electroluminescent material is placed on the outside surface of the CRT. A voltage is applied across the panel so that when ultraviolet energy illuminates the photoconductive material, the voltage change across the panel causes the electroluminescent material to be visible.
Description
United States Patent [191 Potter [451 July 22, 1975 DUAL MODE CRT SCREEN [75] Inventor; Roy F. Potter, San Diego, Calif.
[73] Assignee: The United States of America as represented by the Secretary of the Navy, Washington, DC.
221 Filed: May 28,1974
21 App1.No.:473,987
[52] U.S. Cl 313/463; 313/467 [51] Int. CL WHOIJ 29/18; H01J 31/20; 1101.] 31/12 [58] Field of Search 313/473, 467, 463
[56] References Cited UNITED STATES PATENTS 2,423,830 7/1947 Fonda 313/473 2,861,206 11/1958 Fiore et a1. 313/463 X 2,898,475 3/1959 Larach 313/467 X 3,247,389 4/1966 Kazan 313/463 X 3,344,300 9/1967 Lehrer et a1 313/467 3,780,371 12/1973 Rymes 313/473 3,826,944 7/1974 Cooper 313/473 Primary Examiner-Robert Segal Attorney, Agent, or Firm-R. S. Sciascia; G. J. Rubens; T. M. Phillips [57] ABSTRACT A dual phosphor screen is deposited on the inside surface of the faceplate of a CRT. A photo electroluminescent panel made up of a layer of photoconductive material and a layer of electroluminescent material is placed on the outside surface of the CRT. A voltage is applied across the panel so that when ultraviolet energy illuminates the photoconductive material, the voltage change across the panel causes the electrolu minescent material to be visible.
2 Claims, 2 Drawing Figures 4 .llllllllll m: Alll'l .llulln...
PATENTED L 2 2 I975 ELECTRON FIG.
FIG.2
DUAE MODE CRT SCREEN BACKGROUND OF THE INVENTION In display systems it is often desirable to be able to have long and short persistence on a cathode ray tube used as the display device. In the past, various means have been used to effect dual mode CRT operation. Such means have included color filters combined with dual phosphors having the desired persistence characteristics and spectral responses separated sufficiently in wavelength, and the penetration type using layers of phosphors having the desired characteristics or the onion-skin phosphor shown and described in US. Pat. No. 3,522,463. In the latter the depth of penetration of the cathode ray beam determines which phosphor is excited, thus the control is electronic. However, the higher beam voltages and current required have a deleterious effect upon the phosphor screen and result in shortened tube life. The external filters are undesirable because of mechanical requirements and spectral shortcomings.
SUMMARY OF THE INVENTION The present invention provides a dual mode screen for a cathode ray display tube permitting operation in a short persistence or normal television scan ratio mode and a long persistent mode as in radar displays. The mode switching is accomplished by means of photoelectronically changing the voltage on the luminescent screen.
OBJECTS OF THE INVENTION An object of the invention is the provision of a dual mode screen for a cathode ray display tube permitting operation in short and long persistence modes.
Another object of the invention is the provision of a dual mode screen for a cathode ray display tube permitting operation in short and long persistence modes which overcomes the disadvantages of prior known devices of this type by extending the tube life.
Another object is the provision of a system for electronic switching from long persistence mode to short persistence mode and vice versa of a cathode ray display tube without alteration of the cathode ray beam electronic controls.
A further object is the provision of a dual persistence control wherein the two phosphors can be easily separated in wavelength resulting in a minimum of interference.
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the follow ing detailed description when considered in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a cross-sectional view of a cathode ray tube showing the structure embodying the invention.
FIG. 2 is a schematic diagram showing the electrical circuit associated with the structure of claim 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings wherein there is shown that portion of a cathode ray display tube necessary to illustrate the invention. A dual phosphor screen composed of a mixture of suitable amounts depending upon the desired densities of visible and non-visible emitting phosphor is deposited by standard techniques on the inside of the glass faceplate 12 of a cathode ray tube 14. A photo electroluminescent panel 16 is placed on the external surface of the faceplate I2. Panel 16 consists of a first transparent electrode 18, photoconductive material 20, a second transparent electrode 22, electroluminescent material 24 and a third transparent electrode 26.
Referring to FIG. 2 which is a schematic illustration of the invention. A voltage source 28 is applied across electrodes 18 and 26 when switch 30 is moved from contact 32 to contact 34. The total voltage drop across electrodes 10 and 26 is divided between the photoconductive material 20 and the electroluminescent material 24 such that the electric field across the electroluminescent material is below the critical value for the particular material used. When the photon beam from the excited phospphor strikes photoconductive screen 20, its resistance at that point becomes negligible and the total voltage drop appears across electroluminescent screen 24. That spot on 24 will now be illuminated in the long persistence mode. For the short persistence mode switch 30 is moved from contact 34 to contact 32 to provide a short circuit path that insures the discharge of capacitive voltages that may be present.
In practicing the invention the dual phosphors screen 10 may consist of a mixture of approximately 50% phosphor emitting in the ultraviolet, having medium or long persistence and approximately 50% short persistent green phosphor. The relative percentages may be adjusted to provide the desired densities. The photoelectroluminescent panel 16 is transparent to the dual phosphor green emission when the electric field across electrodes 18 and 26 is zero. Electrodes ll, 18, 22, and 26 may be of any of the conventional transparent type. Photoconductive screen 20 may be, for example, cadmium sulfide or try zinc sulfide while electroluminescent screen 24 may be zinc sulfide. When switch 30 is moved to contact 34 and screen 20 is ultraviolet photo excited, the electric field across electroluminescent screen 24 causes it to emit visible radiation (preferably green).
If preferred, panel 16 may be placed on the inside of the faceplate of the cathode ray tube. It being understood that the electrodes must be appropriately placed to provide the necessary electric fields.
Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
What is claimed is:
1. A multiple mode cathode ray tube screen for presenting a display of differing persistence comprising:
a. an envelope having a viewing area with a screen supporting surface related thereto;
b. a dual phosphor screen formed on the inside of said supporting surface, said dual phosphor screen being composed of a first phosphor material responsive to optical and cathode ray excitation and exhibiting a phosphorescence of substantially short persistence in the visible spectrum and a second phosphor material responsive to optical and cathode ray excitation and exhibiting a phosphorescence in the non-visible spectrum, said dual phosf. a second transparent electrode layered between said photoconductive material and said electroluminescent material;
g. a third transparent electrode layered on the outside surface of said electroluminescent material whereby a voltage may be established across said first and third electrodes that portion of said electro-luminescent material as said phosphor screen is scanned by the electron beam of said cathode ray tube.
2. The screen of claim 1 wherein said ultraviolet material is cadmium sulfide.
Claims (2)
1. A MULTIPLE MODE CATHODE RAY TUBE SCREEN FOR PRESENTING A DISPLAY OF DIFFERING PERSISTENCE COMPRISING: A. AN ENVELOPE HAVING A VIEWING AREA WITH A SCREEN SUPPORTING SURFACE RELATED THERETO, B. A DUAL PHOSPHOR SCREEN FORMED ON THE INSIDE OF SAID SUPPORTING SURFACE, SAID DUAL PHOSPHOR SCREEN BEING COMPOSED OF A FIRST PHOSPHOR MATERIAL RESPONSIVE TO OPTICAL AND CATHODE RAY EXCITATION AND EXIBITING A PHOSPHORESCENCE OF SUBSTANTIALLY SHORT PERSISTENCE IN THE VISIBLE SPECTRUM AND A SECOND PHOSPHOR MATERIAL RESPONSIVE TO OPTICAL AND CATHODE RAY EXCITATION AND EXHIBITING A PHOSOPHORESCENCE IN THE NON-VISIBLE SPECTRUM, AND DUAL PHOSPHOR MATERIAL BEING APPROXIMATELY 50% PHOSPHOR EMITTING IN THE ULTRAVIOET, HAVING MEDIUM OR LONG PERSISTENCE, AND APPROXAMATELY 50% SHORT PERSISTENCE GREEN PHOSPHOR, AND SAID PHOTOCONDUCIVE MATERIAL BEING ULTRAVIOLET SENSITIVE, C. A PHOTOCONDUCIVE MATERIAL WHOSE RESISTANCE BECOMES NEGLIGIBLE PHOSPHORESCENCE, NON-VISIBLE PHOSPHORESCENCE, D. A FIRST TRANSPARENT ELECTRODE LAYERED BETWEEN THE OUTSIDE SURFACE OF SAID FACE PLATE ANND SAID PHOTOCONDUCIVE MATERIAL, E. AN ELECTROLUMINESCENT MATERIAL RESPONSIVE TO EXCIATION BY THEPRESENCE OF AN ELECTRIC FIELD, F. A SECOND TRANSPARENT ELECTRODE LAYER BETWEEN SAID PHOTOCONODUCIVE MATERIAL AND SAID ELECTROLUMINESCENT MATERIAL, G. A THIRD TRANSPARENT ELECTRODE LAYER ON THE OUTSIDE SRFACE OF SAID ELECTROLUMINESCENT MATERIAL WHEREBY A VOLTAGE MAY BE ESTABLISHED ACROSS SAID FIRST AND THIRD ELECTRODES THAT PORTION OF SAID ELECTRKO-LUMINESCENT MATERIAL AS SAID PHOSPER SCREEN IS SCANNED BY THE ELECTRON BEAM OF SAID CATHODE RAY TUBE.
2. The screen of claim 1 wherein said ultraviolet material is cadmium sulfide.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US473987A US3896328A (en) | 1974-05-28 | 1974-05-28 | Dual mode crt screen |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US473987A US3896328A (en) | 1974-05-28 | 1974-05-28 | Dual mode crt screen |
Publications (1)
Publication Number | Publication Date |
---|---|
US3896328A true US3896328A (en) | 1975-07-22 |
Family
ID=23881778
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US473987A Expired - Lifetime US3896328A (en) | 1974-05-28 | 1974-05-28 | Dual mode crt screen |
Country Status (1)
Country | Link |
---|---|
US (1) | US3896328A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4249133A (en) * | 1978-07-10 | 1981-02-03 | Tektronix, Inc. | Electroluminescent cathode ray storage tube |
US20030055686A1 (en) * | 2001-09-20 | 2003-03-20 | Sharp Kabushiki Kaisha | Medical information system |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2423830A (en) * | 1943-03-25 | 1947-07-15 | Gen Electric | Cathode-ray screen having contrasting colors and unlike rates of decay of luminescence |
US2861206A (en) * | 1955-12-29 | 1958-11-18 | Zenith Radio Corp | Color image reproducers |
US2898475A (en) * | 1955-10-06 | 1959-08-04 | Rca Corp | Light intensifier |
US3247389A (en) * | 1952-10-20 | 1966-04-19 | Rca Corp | Electroluminescent device for producing images |
US3344300A (en) * | 1965-03-23 | 1967-09-26 | Hughes Aircraft Co | Field sustained conductivity devices with cds barrier layer |
US3780371A (en) * | 1969-07-28 | 1973-12-18 | Us Navy | Electronic counter-countermeasures system |
US3826944A (en) * | 1970-06-04 | 1974-07-30 | Westinghouse Electric Corp | Cathode ray tube with inorganic phosphor and fiber optic face plate |
-
1974
- 1974-05-28 US US473987A patent/US3896328A/en not_active Expired - Lifetime
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2423830A (en) * | 1943-03-25 | 1947-07-15 | Gen Electric | Cathode-ray screen having contrasting colors and unlike rates of decay of luminescence |
US3247389A (en) * | 1952-10-20 | 1966-04-19 | Rca Corp | Electroluminescent device for producing images |
US2898475A (en) * | 1955-10-06 | 1959-08-04 | Rca Corp | Light intensifier |
US2861206A (en) * | 1955-12-29 | 1958-11-18 | Zenith Radio Corp | Color image reproducers |
US3344300A (en) * | 1965-03-23 | 1967-09-26 | Hughes Aircraft Co | Field sustained conductivity devices with cds barrier layer |
US3780371A (en) * | 1969-07-28 | 1973-12-18 | Us Navy | Electronic counter-countermeasures system |
US3826944A (en) * | 1970-06-04 | 1974-07-30 | Westinghouse Electric Corp | Cathode ray tube with inorganic phosphor and fiber optic face plate |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4249133A (en) * | 1978-07-10 | 1981-02-03 | Tektronix, Inc. | Electroluminescent cathode ray storage tube |
US20030055686A1 (en) * | 2001-09-20 | 2003-03-20 | Sharp Kabushiki Kaisha | Medical information system |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4155030A (en) | Multicolor display device using electroluminescent phosphor screen with internal memory and high resolution | |
US3875442A (en) | Display panel | |
US6242865B1 (en) | Field emission display device with focusing electrodes at the anode and method for constructing same | |
US6084345A (en) | Field emission display devices | |
US3838307A (en) | Color plasma display | |
US6023126A (en) | Edge emitter with secondary emission display | |
US6011356A (en) | Flat surface emitter for use in field emission display devices | |
US4654649A (en) | Display device | |
US20070222394A1 (en) | Black matrix for flat panel field emission displays | |
US3825922A (en) | Channel plate display device having positive optical feedback | |
US4140941A (en) | Cathode-ray display panel | |
US5945777A (en) | Surface conduction emitters for use in field emission display devices | |
US3896328A (en) | Dual mode crt screen | |
US4149108A (en) | Multistable cathode ray type storage display device | |
US2888593A (en) | Cathode ray tube | |
Josephs | A review of panel-type display devices | |
US2879444A (en) | Display screen for television tubes | |
US4301388A (en) | Color coding of write-through information in direct viewing bistable storage CRT display | |
US2872613A (en) | Color image screen utilizing electroluminescence | |
RU2095880C1 (en) | Autoelectronic device | |
KR100301759B1 (en) | Thick film-type electroluminescence device | |
Baltag | History of Plasma Display Reflected by Patents | |
US3609441A (en) | Field-effect viewing storage tube | |
KR100207577B1 (en) | Plasma display panel | |
JP2723715B2 (en) | Fluorescent display tube |