US3590302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensated convergence coil for cathode ray tubes
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1969-09-02
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Granted: 1971-06-29
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Expires: 1989-09-02
Abstract
Abstract Convergence coil assembly for multigun cathode ray tubes in which changes in magnetic permeability due to changes in temperature are compensated by the provision of a temperature compensating shunting element in the core structure whose change in permeability upon temperature change tends to keep the available flux density affecting the electron beam at a constant value.
Inventors
- 👤 Robert W Bussey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:23
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/70; H01J29/701; H01J29/702; H01J29/006; H01J2229/00; H01J2229/56; H01J2229/568; H01J2229/5681; H01J2229/5682
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
139 words
A convergence coil assembly for a multibeam cathode ray tube comprising a plurality of magnet assemblies arranged to be positioned on the neck of said tube, one magnet assembly being in proximity to each of the electRon beams therein to thereby affect the inclination of its associated beam for convergence of the beams at the face of said tube, each of said magnet assemblies including a permanent magnet composed of a material having a negative temperature coefficient of magnetic permeability and pole pieces disposed in the field of said magnet, said pole pieces being separated by a nonmagnetic gap, and a temperature sensitive spacer within the magnetic field of said magnet assembly and shunting a portion of said magnetic field thereby reducing the deflection of the beams from their converged positions due to temperature changes in the magnet assemblies.
Claim 2
Dependent Claim
139 words
A convergence coil assembly for a multibeam cathode ray tube comprising a plurality of magnet assemblies arranged to be positioned on the neck of said tube, one magnet assembly being in proximity to each of the electRon beams therein to thereby affect the inclination of its associated beam for convergence of the beams at the face of said tube, each of said magnet assemblies including a permanent magnet composed of a material having a negative temperature coefficient of magnetic permeability and pole pieces disposed in the field of said magnet, said pole pieces being separated by a nonmagnetic gap, and a temperature sensitive spacer within the magnetic field of said magnet assembly and shunting a portion of said magnetic field thereby reducing the deflection of the beams from their converged positions due to temperature changes in the magnet assemblies.
Claim 3
Dependent Claim
18 words
The convergence coil assembly of claim 1 in which said permanent magnet is composed of a barium ferrite.
Claim 4
Dependent Claim
30 words
The convergence coil assembly of claim 1 in which said spacer includes a strip of metal having a negative temperature coefficient of magnetic permeability associated with a nonmagnetic dielectric material.
Claim 5
Dependent Claim
34 words
The convergence coil of claim 3 in which said strip has a medial portion received between confronting faces of said pole pieces and leg portions engaging opposed faces of one of said pole pieces.
Claim 6
Dependent Claim
15 words
The convergence coil assembly of claim 3 in which said nonmagnetic dielectric material is paper.
Claim 7
Dependent Claim
36 words
The convergence coil assembly of claim 1 in which said permanent magnet is disposed against said nonmagnetic gap and has adjustment means acting on said permanent magnet for varying the magnetic field strength at said gap.
Claim 8
Dependent Claim
27 words
The convergence coil assembly of claim 1 in which said pole pieces are L-shaped and said spacer is located in the nonmagnetic gap between said pole pieces.
Claim 9
Dependent Claim
66 words
In a convergence coil assembly for cathode ray tubes and the like, having at least one beam path whose position is to be modified, which assembly has a magnet and pole pieces separated by a nonmagnetic gap for controlling the position of a beam path, the improvement of a temperature compensating spacer in said gap effective to offset the effect of temperature changes on the magnet.
Claim 10
Dependent Claim
66 words
In a convergence coil assembly for cathode ray tubes and the like, having at least one beam path whose position is to be modified, which assembly has a magnet and pole pieces separated by a nonmagnetic gap for controlling the position of a beam path, the improvement of a temperature compensating spacer in said gap effective to offset the effect of temperature changes on the magnet.
References Cited (Backward Citations)
US3002120A
Cited
US3325758A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |