Patent US3840765A successfully refreshed from Google Patents.
US3840765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shielding member between only the control and side beams in a color cathode ray tube
Assignee: Toshiba Corp
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Filing: 1972-09-26
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Granted: 1974-10-08
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Expires: 1992-09-26
Abstract
Abstract A color cathode ray tube has a beam convergence device for converging and compensating a central beam and a pair of side beams which have the central beam interposed therebetween. Said central and side beams are projected from three electron guns which are aligned in line and provided inside the neck portion of the tube envelope. The beam convergence device includes a pair of convergence magnetic field generators mounted on the outer surface of the neck portion of the tube envelope and a pair of magnetic field shielding plates arranged between the central beam and one of side beams and between the central beam and the other of side beams respectively so as to oppose to the respective one of the paired convergence magnetic field generators, the respective one of magnetic field shielding plates having a convex surface projecting in the direction of the central beam. The color cathode ray tube thus constructed is prominent and successful in that by means of the pair of magnetic field shielding plates, the influence of magnetic field applied to the convergence magnetic field generator from the electromagnetic deflection device is made more uniform.
Inventors
- 👤 S Takenaka
- 👤 K Idaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:15
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/70; H01J29/701; H01J29/707
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
191 words
A color cathode ray tube comprising: a tube envelope having a neck portion; an electromagnetic deflection device for generating horizontal deflection flux and vertical deflection flux for horizontally and vertically deflecting electron beams; a beam convergence device for generating a convergence magnetic field; an electron gun device mounted inside the neck portion of said tube, said electron gun device including an in-line electron gun assembly for projecting a central electron beam and a pair of side electron beams, said three electron beams being disposed on a plane perpendicular to the horizontal deflection flux generated by said electromagnetic deflection device; and a pair of magnetic shielding members positioned only between the central electron beam and each of the side electron beams, respectively, said shielding members running in the convergence magnetic field of said convergence device and extending along the lines perpendicular to said plane of said electron beams such that said three electron beams are open to said horizontal deflection flux, thereby not shielding the hOrizontal deflection magnetic flux acting on said side beams, each of said shielding members having a raised portion protruding in the direction of said central electron beam.
Claim 2
Dependent Claim
191 words
A color cathode ray tube comprising: a tube envelope having a neck portion; an electromagnetic deflection device for generating horizontal deflection flux and vertical deflection flux for horizontally and vertically deflecting electron beams; a beam convergence device for generating a convergence magnetic field; an electron gun device mounted inside the neck portion of said tube, said electron gun device including an in-line electron gun assembly for projecting a central electron beam and a pair of side electron beams, said three electron beams being disposed on a plane perpendicular to the horizontal deflection flux generated by said electromagnetic deflection device; and a pair of magnetic shielding members positioned only between the central electron beam and each of the side electron beams, respectively, said shielding members running in the convergence magnetic field of said convergence device and extending along the lines perpendicular to said plane of said electron beams such that said three electron beams are open to said horizontal deflection flux, thereby not shielding the hOrizontal deflection magnetic flux acting on said side beams, each of said shielding members having a raised portion protruding in the direction of said central electron beam.
Claim 3
Dependent Claim
36 words
A color cathode ray tube according to claim 1 wherein each of said magnetic shielding members are curved plates, each plate being curved such that its outermost extending surface portion corresponds to said raised central portion.
Claim 4
Dependent Claim
29 words
A color cathode ray tube according to claim 1 wherein said magnetic shielding members are smoothly curved and are generally in the shape of an arc of a circle.
Claim 5
Dependent Claim
31 words
A color cathode ray tube according to claim 1 wherein each of said magnetic shielding members has a step-like protrusion extending therefrom and which corresponds to the respective raised central portions.
Claim 6
Dependent Claim
191 words
A color cathode ray tube comprising: a tube envelope having a neck portion; an electromagnetic deflection device for generating horizontal deflection flux and vertical deflection flux for horizontally and vertically deflecting electron beams; a beam convergence device for generating a convergence magnetic field; an electron gun device mounted inside the neck portion of said tube, said electron gun device including an in-line electron gun assembly for projecting a central electron beam and a pair of side electron beams, said three electron beams being disposed on a plane perpendicular to the horizontal deflection flux generated by said electromagnetic deflection device; and a pair of magnetic shielding members positioned only between the central electron beam and each of the side electron beams, respectively, said shielding members running in the convergence magnetic field of said convergence device and extending along the lines perpendicular to said plane of said electron beams, each of said shielding members having a raised portion protruding in the direction of said central electron beam for reducing the reluctance between said raised portions against the rear portion of the deflection magnetic field intruding between said pair of magnetic field shielding plates.
Claim 7
Dependent Claim
191 words
A color cathode ray tube comprising: a tube envelope having a neck portion; an electromagnetic deflection device for generating horizontal deflection flux and vertical deflection flux for horizontally and vertically deflecting electron beams; a beam convergence device for generating a convergence magnetic field; an electron gun device mounted inside the neck portion of said tube, said electron gun device including an in-line electron gun assembly for projecting a central electron beam and a pair of side electron beams, said three electron beams being disposed on a plane perpendicular to the horizontal deflection flux generated by said electromagnetic deflection device; and a pair of magnetic shielding members positioned only between the central electron beam and each of the side electron beams, respectively, said shielding members running in the convergence magnetic field of said convergence device and extending along the lines perpendicular to said plane of said electron beams, each of said shielding members having a raised portion protruding in the direction of said central electron beam for reducing the reluctance between said raised portions against the rear portion of the deflection magnetic field intruding between said pair of magnetic field shielding plates.
Claim 8
Dependent Claim
36 words
A color cathode ray tube according to claim 5 wherein each of said magnetic shielding members are curved plates, each plate being curved such that its outermost extending surface portion corresponds to said raised central portion.
Claim 9
Dependent Claim
29 words
A color cathode ray tube according to claim 5 wherein said magnetic shielding members are smoothly curved and are generally in the shape of an arc of a circle.
Claim 10
Dependent Claim
31 words
A color cathode ray tube according to claim 5 wherein each of said magnetic shielding members has a step-like protrusion extending therefrom and which corresponds to the respective raised central portions.
Claim 11
Dependent Claim
16 words
A color cathode ray tube according to claim 1 wherein said shielding members are respective plates.
Claim 12
Dependent Claim
16 words
A color cathode ray tube according to claim 5 wherein said shielding members are respective plates.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |