Patent US3876898A successfully refreshed from Google Patents.
US3876898A
Expired / Lapsed
US
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Shielding means for a cathode ray tube
Assignee: GTE Sylvania Inc
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Filing: 1974-06-27
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Granted: 1975-04-08
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Expires: 1994-06-27
Abstract
Abstract Improved shielding means are provided in a post-deflection type of color cathode ray tube for effectively removing the cloud of spurious low-velocity secondary electrons from the interior of the tube particularly from the region on the electron gun side of the color-selection electrode. The shielding means is comprised of a defined electrical conductive area of screen potential disposed relative to the interior surface of the tube funnel portion and extended partially therealong in an axially related direction. Associated therewith is a metallic shielding member spaced therefrom and affixed to the framing portion of the colorselection electrode. The shielding member has provisions for defining at least one opening proximally facing the conductive area through which a penetrating potential collects the spurious secondary electrons.
Inventors
- 👤 Charles A Davis
- 👤 Donald L Say
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:02
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
250 words
Improved shielding means for use in a post-deflection color cathode ray tube having a longitudinal axis therethrough and incorporating an envelope-traversing electrical conductor for applying a separate electrical potential to the screen therein, said tube envelope being formed of an integration of a neck portion having an electron gun assembly positioned therein, a funnel portion joined thereto, with said funnel portion being sequentially sealed to a contiguous panel portion having a patterned cathodoluminescent screen formed on the inner surface thereof, and wherein a frame supported color-selection-electrode is oriented in spatial relationship thereto, said improved shielding means comprising: at least one defined electrical conductive area of screen potential disposed relative to the interior surface of said funnel portion in the region adjacent to the seal joining said funnel and panel portions, said area having an effective dimension extending into the funnel portion from the plane of the framing member of the color-selection electrode in an axially related direction for a partial distance thereinto relative to said seal; and a metallic shielding member interiorly spaced from said funnel-related screen potential conductive area and positionally affixed on the framing portion of said color selection electrode in a manner to extend a partial distance into said funnel portion, said shielding member being of colorselection-electrode potential and having provisions for defining at least one opening proximally facing said conductive area of screen potential and distally facing said axis, the height of said defined opening being related to the extending dimension of said related conductive area.
Claim 2
Dependent Claim
250 words
Improved shielding means for use in a post-deflection color cathode ray tube having a longitudinal axis therethrough and incorporating an envelope-traversing electrical conductor for applying a separate electrical potential to the screen therein, said tube envelope being formed of an integration of a neck portion having an electron gun assembly positioned therein, a funnel portion joined thereto, with said funnel portion being sequentially sealed to a contiguous panel portion having a patterned cathodoluminescent screen formed on the inner surface thereof, and wherein a frame supported color-selection-electrode is oriented in spatial relationship thereto, said improved shielding means comprising: at least one defined electrical conductive area of screen potential disposed relative to the interior surface of said funnel portion in the region adjacent to the seal joining said funnel and panel portions, said area having an effective dimension extending into the funnel portion from the plane of the framing member of the color-selection electrode in an axially related direction for a partial distance thereinto relative to said seal; and a metallic shielding member interiorly spaced from said funnel-related screen potential conductive area and positionally affixed on the framing portion of said color selection electrode in a manner to extend a partial distance into said funnel portion, said shielding member being of colorselection-electrode potential and having provisions for defining at least one opening proximally facing said conductive area of screen potential and distally facing said axis, the height of said defined opening being related to the extending dimension of said related conductive area.
Claim 3
Dependent Claim
89 words
The improved shielding means according to claim 1 wherein said defined conductive area of screen potential is a longitudinal formation extending from the periphery of said screen into said funnel portion, said conductive formation comprising an envelope-traversing electrical conductor in the form of a metallic conductive button disposed in the wall of said funnel portion adjacent the panel-funnel seal, and a substantially longitudinal resilient metallic connective member affixed to the interior surface of said funnel-disposed button and extended therefrom to make contact with a peripheral portion of said screen.
Claim 4
Dependent Claim
83 words
Improved shielding means according to claim 1 wherein said defined conductive area of screen potential is a longitudinal formation of conductive coating applied to the wall of the funnel portion longitudinally dimensionally extending in an axially related direction therealong from a region adjacent the panel-funnel seal, and wherein said envelope-traversing electrical conductor is disposed through said panel-funnel seal in a manner to make internal pressured electrical connections with said strip of said funnel disposed conductive coating and a peripheral portion of said screen.
Claim 5
Dependent Claim
89 words
Improved shielding means according to claim 1 wherein said defined conductive area of screen potential is in the form of a band of conductive coating interiorly applied in a peripheral manner about said funnel and having a height dimensionally extending in an axially related direction from the region adjacent the panel seal, and wherein said envelope traversing electrical conductor is disposed through said panel-funnel seal in a manner to make internal pressured electrical connections with said band of funnel disposed conductive coating and a peripheral portion of said screen.
Claim 6
Dependent Claim
56 words
Improved shielding means according to claim 1 wherein said metallic shielding member spaced from said funnel related screen potential conductive area is a substantially inverted U-shaped wire having the ends thereof positionally affixed to the framing portion of the color-selection electrode, said U-shaped wire being oriented thereon in a manner to extend into said funnel portion.
Claim 7
Dependent Claim
66 words
Improved shielding means according to claim 1 wherein said metallic shielding member spaced from said funnel-related screen potential conductive area is in the form of standing perimetrically oriented wall affixed to the framing portion of said color-selection electrode in a manner to spatially extend into said funnel portion, said wall-like member having at least one defined opening therein facing said funnel-related conductive area of screen potential.
Claim 8
Dependent Claim
40 words
The improved shielding means according to claim 1 wherein said defined electrical conductive area of screen potential has an effective extending dimension not exceeding about twenty-five percent of the funnel distance from the seal edge to the neck-related portion thereof.
Claim 9
Dependent Claim
110 words
Improved shielding means according to claim 1 wherein said defined conductive area of screen potential is in the form of a band of conductive coating interiorly applied in a peripheral manner about said funnel and having a height dimensionally extending in an axially related direction from the region adjacent the panel seal, and wherein said envelope-traversing electrical conductor is in the form of a metallic conductive button disposed in the wall of said funnel portion adjacent the panel-funnel seal, making contact with said band of coating and wherefrom a substantially longitudinally resilient metallic connective member affixed to said button extends to make contact with a peripheral portion of said screen.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |