US2343630A - Shield for cathode ray tubes - Google Patents
Shield for cathode ray tubes Download PDFInfo
- Publication number
- US2343630A US2343630A US440453A US44045342A US2343630A US 2343630 A US2343630 A US 2343630A US 440453 A US440453 A US 440453A US 44045342 A US44045342 A US 44045342A US 2343630 A US2343630 A US 2343630A
- Authority
- US
- United States
- Prior art keywords
- shield
- cathode ray
- tube
- ray tubes
- magnetic
- 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
- 239000002184 metal Substances 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 9
- 239000011230 binding agent Substances 0.000 description 7
- 239000002245 particle Substances 0.000 description 6
- 230000035699 permeability Effects 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 239000004020 conductor Substances 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 229920002160 Celluloid Polymers 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 230000012447 hatching Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 239000013528 metallic particle Substances 0.000 description 1
- 229910000595 mu-metal Inorganic materials 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin 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
- H01J29/86—Vessels; Containers; Vacuum locks
- H01J29/867—Means associated with the outside of the vessel for shielding, e.g. magnetic shields
Definitions
- This invention relates to a shield for a cathode ray tube which shields the tube from magnetic as well as electrostatic influences. It is primarily for the purpose of shielding the electron beam of the tube from both magnetic and electrostatic stray fields so that errors of deflection of the beam will be avoided.
- an electrostatic and magnetic shield of high magnetic permeability is applied to the outside surface of the cathode ray tube in such a way that it does not in any way interfere with the normal operation of the tube or add very materially to the cost thereof.
- FIG. 1 indicates a cathode ray tube having the usual metallic base 2 with center pin 3 and a circular row of contact pins 4.
- the structure inside the tube for generating and deflecting the cathode ray may be made up of any of the known sorts. They are not shown as they do not constitute any part of this invention.
- the external portion of a connector for making electrical connection from a source of high potential to the customary intensifier for the cathode ray beam located inside the tube is shown at 5.
- the magnetic and electrostatic shield 6 for the tube i is applied to the outer surface thereof and is shown in section by the cross hatching. It is applied to the tube I from a region at or near the metal base 2 nearly to the outer or large end of the tube. A hole I is provided through the shield 6 so that it will not contact with the connector 5. A metal Jumper or band 8 connects the shield 6 electrically to the metal base 2.
- the shield Bis made up of finely granulated material of high magnetic permeability in weak magnetic fields. This material is also of good electrical conductivity. For example, particles of mu metal, which is an alloy of iron and nickel, or pure iron. or other magnetically permeable and electrically conductive material may be used for preparing the shield 6.
- the metallic material for the shield 6 is finely divided or disintegrated and suspended in a binder and the suspension is applied to or coated upon the outer surface of the cathode ray tube l in any convenient way as by brushing or spraying it on, for example, until a sufilciently thick layer is provided to exclude magnetic fields 0f the order of 0.5 gauss. Thicknesses of 0.15 inch have been found to be suflicient in most cases.
- the suspension material or binder to be used may be of a variety of materials such as a Celluloid base binder, synthetic resin, asphalt, etc., that will adhere to the surface of the tube and retain the metallic particles in place.
- the amount of the metal particles in the binder is sufiiciently large to cause enough contact of the particles with each other to make the coating 8 electricallyconductive.
- a magnetic and electrostatic shield for a cathode ray tube having a metal base comprising particles of electrically conductive material of high magnetic permeability applied in an adhesive binder to said tube. said shield being separated from but electrically connected to the metal base of said tube.
- a magnetic and electrostatic shield of high magnetic permeability for a cathode ray tube having a metal base comprising a thick coating of particles of electrically conductive material of high magnetic permeability applied in an adhesive bihder to said tube, the amount of said particles in said binder being sufllcient to make the shield electrically conductive, said shield being separated from but electrically connected to said metal base.
- A.magnetic and electrostatic shield for a cathode ray tube having a metal base comprising a coating of enough particles of electrically conductive material of high magnetic permeability in an adhesive binder on said tube to make the coating electrically conductive, said shield being separated from but electrically connected to said metal base.
Landscapes
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Description
March 7, 1944. w JR 2,343,630
SHIELD FOR CATHODE RAY TUBES Filed April 25, 1942 My 7 Y INVENTOR.
ll TTORNEY Patented Mar. 7, 1944 SHIELD FOR CATHODE RAY TUBES Horace Atwood, Jr., Passaic, N. 1., assignor to Allen 13. Du Mont Laboratories, Inc., Passaic. N. J., a corporation of Delaware Application April 25, 1942, Serial No. 440,453
3 Claims.
This invention relates to a shield for a cathode ray tube which shields the tube from magnetic as well as electrostatic influences. It is primarily for the purpose of shielding the electron beam of the tube from both magnetic and electrostatic stray fields so that errors of deflection of the beam will be avoided.
In carrying out the invention an electrostatic and magnetic shield of high magnetic permeability is applied to the outside surface of the cathode ray tube in such a way that it does not in any way interfere with the normal operation of the tube or add very materially to the cost thereof.
The invention may be understood from the description in connection with the accompanying drawing which is a side view of a cathode ray tube showing in section a magnetic and electrostatic shield applied to the tube.
In the drawing reference character I indicates a cathode ray tube having the usual metallic base 2 with center pin 3 and a circular row of contact pins 4. The structure inside the tube for generating and deflecting the cathode ray may be made up of any of the known sorts. They are not shown as they do not constitute any part of this invention. The external portion of a connector for making electrical connection from a source of high potential to the customary intensifier for the cathode ray beam located inside the tube is shown at 5.
The magnetic and electrostatic shield 6 for the tube i is applied to the outer surface thereof and is shown in section by the cross hatching. It is applied to the tube I from a region at or near the metal base 2 nearly to the outer or large end of the tube. A hole I is provided through the shield 6 so that it will not contact with the connector 5. A metal Jumper or band 8 connects the shield 6 electrically to the metal base 2.
The shield Bis made up of finely granulated material of high magnetic permeability in weak magnetic fields. This material is also of good electrical conductivity. For example, particles of mu metal, which is an alloy of iron and nickel, or pure iron. or other magnetically permeable and electrically conductive material may be used for preparing the shield 6.
The metallic material for the shield 6 is finely divided or disintegrated and suspended in a binder and the suspension is applied to or coated upon the outer surface of the cathode ray tube l in any convenient way as by brushing or spraying it on, for example, until a sufilciently thick layer is provided to exclude magnetic fields 0f the order of 0.5 gauss. Thicknesses of 0.15 inch have been found to be suflicient in most cases. The suspension material or binder to be used may be of a variety of materials such as a Celluloid base binder, synthetic resin, asphalt, etc., that will adhere to the surface of the tube and retain the metallic particles in place. The amount of the metal particles in the binder is sufiiciently large to cause enough contact of the particles with each other to make the coating 8 electricallyconductive.
What is claimed is:
1. A magnetic and electrostatic shield for a cathode ray tube having a metal base, comprising particles of electrically conductive material of high magnetic permeability applied in an adhesive binder to said tube. said shield being separated from but electrically connected to the metal base of said tube.
2. A magnetic and electrostatic shield of high magnetic permeability for a cathode ray tube having a metal base, comprising a thick coating of particles of electrically conductive material of high magnetic permeability applied in an adhesive bihder to said tube, the amount of said particles in said binder being sufllcient to make the shield electrically conductive, said shield being separated from but electrically connected to said metal base.
3. A.magnetic and electrostatic shield for a cathode ray tube having a metal base, comprising a coating of enough particles of electrically conductive material of high magnetic permeability in an adhesive binder on said tube to make the coating electrically conductive, said shield being separated from but electrically connected to said metal base.
HORACE ATWOOD, Jn.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US440453A US2343630A (en) | 1942-04-25 | 1942-04-25 | Shield for cathode ray tubes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US440453A US2343630A (en) | 1942-04-25 | 1942-04-25 | Shield for cathode ray tubes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2343630A true US2343630A (en) | 1944-03-07 |
Family
ID=23748813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US440453A Expired - Lifetime US2343630A (en) | 1942-04-25 | 1942-04-25 | Shield for cathode ray tubes |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2343630A (en) |
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2465354A (en) * | 1946-03-16 | 1949-03-29 | Standard Telephones Cables Ltd | Oscillograph |
| US2497660A (en) * | 1945-06-18 | 1950-02-14 | Gen Electric | Leakage minimizing shield for electron discharge devices |
| US2512247A (en) * | 1946-08-07 | 1950-06-20 | X Ray Electronic Corp | Antimagnetically shielded photocell |
| US2523406A (en) * | 1949-06-25 | 1950-09-26 | Remington Rand Inc | Insulated anode for cathode-ray tubes |
| US2604599A (en) * | 1949-09-17 | 1952-07-22 | Sylvania Electric Prod | Cathode-ray tube |
| US2703373A (en) * | 1949-06-21 | 1955-03-01 | Gen Electric | X-ray tube |
| US2774002A (en) * | 1954-12-21 | 1956-12-11 | Itt | Image tube |
| US2801360A (en) * | 1952-08-23 | 1957-07-30 | Bell Telephone Labor Inc | Traveling wave tube |
| US2907914A (en) * | 1954-05-26 | 1959-10-06 | Magnetic Metals Company | Electrically energized magnetic shield |
| US3249466A (en) * | 1960-02-16 | 1966-05-03 | Owens Illinois Inc | Magnetic solder glass coatings and method |
| US3345537A (en) * | 1965-02-12 | 1967-10-03 | Melpar Inc | Photoelectric shield including a dielectric sheet sandwiched between two metal sheets |
| US3377504A (en) * | 1964-06-27 | 1968-04-09 | Chirana Praha | X-ray image intensifier tube with magnetically shielding mounting sleeve secured to envelope |
| US3584252A (en) * | 1969-05-23 | 1971-06-08 | Wagner Electric Corp | Electrically-shielded symbol-display tube |
| US3614519A (en) * | 1967-12-18 | 1971-10-19 | Zenith Radio Corp | Cathode-ray tube magnetic shield |
| US4152745A (en) * | 1977-04-11 | 1979-05-01 | Eul Edward A | Magnetic shield device |
| US4556821A (en) * | 1984-03-15 | 1985-12-03 | Rca Corporation | Color image display system having an improved external magnetic shield |
| US5304891A (en) * | 1991-06-28 | 1994-04-19 | Mitsubishi Denki Kabushiki Kaisha | Cathode-ray tube display device |
| US6765806B1 (en) * | 2001-06-12 | 2004-07-20 | Lsi Logic Corporation | Composition with EMC shielding characteristics |
-
1942
- 1942-04-25 US US440453A patent/US2343630A/en not_active Expired - Lifetime
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2497660A (en) * | 1945-06-18 | 1950-02-14 | Gen Electric | Leakage minimizing shield for electron discharge devices |
| US2465354A (en) * | 1946-03-16 | 1949-03-29 | Standard Telephones Cables Ltd | Oscillograph |
| US2512247A (en) * | 1946-08-07 | 1950-06-20 | X Ray Electronic Corp | Antimagnetically shielded photocell |
| US2703373A (en) * | 1949-06-21 | 1955-03-01 | Gen Electric | X-ray tube |
| US2523406A (en) * | 1949-06-25 | 1950-09-26 | Remington Rand Inc | Insulated anode for cathode-ray tubes |
| US2604599A (en) * | 1949-09-17 | 1952-07-22 | Sylvania Electric Prod | Cathode-ray tube |
| US2801360A (en) * | 1952-08-23 | 1957-07-30 | Bell Telephone Labor Inc | Traveling wave tube |
| US2907914A (en) * | 1954-05-26 | 1959-10-06 | Magnetic Metals Company | Electrically energized magnetic shield |
| US2774002A (en) * | 1954-12-21 | 1956-12-11 | Itt | Image tube |
| US3249466A (en) * | 1960-02-16 | 1966-05-03 | Owens Illinois Inc | Magnetic solder glass coatings and method |
| US3377504A (en) * | 1964-06-27 | 1968-04-09 | Chirana Praha | X-ray image intensifier tube with magnetically shielding mounting sleeve secured to envelope |
| US3345537A (en) * | 1965-02-12 | 1967-10-03 | Melpar Inc | Photoelectric shield including a dielectric sheet sandwiched between two metal sheets |
| US3614519A (en) * | 1967-12-18 | 1971-10-19 | Zenith Radio Corp | Cathode-ray tube magnetic shield |
| US3584252A (en) * | 1969-05-23 | 1971-06-08 | Wagner Electric Corp | Electrically-shielded symbol-display tube |
| US4152745A (en) * | 1977-04-11 | 1979-05-01 | Eul Edward A | Magnetic shield device |
| US4556821A (en) * | 1984-03-15 | 1985-12-03 | Rca Corporation | Color image display system having an improved external magnetic shield |
| US5304891A (en) * | 1991-06-28 | 1994-04-19 | Mitsubishi Denki Kabushiki Kaisha | Cathode-ray tube display device |
| US6765806B1 (en) * | 2001-06-12 | 2004-07-20 | Lsi Logic Corporation | Composition with EMC shielding characteristics |
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