US4642695A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection cathode-ray tube having enhanced image brightness
Assignee: Mitsubishi Electric Corp
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Filing: 1984-10-30
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Granted: 1987-02-10
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Expires: 2004-10-30
Abstract
Abstract A projection cathode-ray tube comprises a vacuum vessel (10) having a face plate (7), an interference thin film (20) on the inner surface of the face plate, a phosphor layer (8) on the interference thin film, a metal-back film (9) on the phosphor layer and an electron gun within the vessel. More than 30% of the total luminous flux from an emission point in the phosphor layer to which the electron beam of the electron gun is applied exists within a divergent angle of ± 30° in the direction normal to the face plate.
Inventors
- 👤 Yasuo Iwasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:19
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/28; H01J29/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
125 words
A projection cathode-ray tube comprising a vacuum vessel having a face plate, a phosphor layer on an inner surface of said face plate, an interference thin film between the inner surface of said face plate and an outer surface of said phosphor layer, a metal-back film on an inner surface of said phosphor layer and an electron gun within said vessel, wherein an image on said phosphor layer is enlarged and projected on a screen located at a given distance ahead through a projection lens in front of said face plate, such that more than 30% of all luminous flux emitted from an emission point in said phosphor layer is concentrated within a divergent angle of ±30° in a direction normal to said face plate.
Claim 2
Dependent Claim
125 words
A projection cathode-ray tube comprising a vacuum vessel having a face plate, a phosphor layer on an inner surface of said face plate, an interference thin film between the inner surface of said face plate and an outer surface of said phosphor layer, a metal-back film on an inner surface of said phosphor layer and an electron gun within said vessel, wherein an image on said phosphor layer is enlarged and projected on a screen located at a given distance ahead through a projection lens in front of said face plate, such that more than 30% of all luminous flux emitted from an emission point in said phosphor layer is concentrated within a divergent angle of ±30° in a direction normal to said face plate.
Claim 3
Dependent Claim
27 words
A projection cathode-ray tube in accordance with claim 1, characterized in that phosphor particles in said phosphor layer are of plate-like crystal parallel to said face plate.
Claim 4
Dependent Claim
27 words
A projection cathode-ray tube in accordance with claim 1, characterized in that phosphor particles in said phosphor layer are of plate-like cyrstal parallel to said face plate.
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) | 1990-02-09 | 1990-08-11 | 1991-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-09 | 1994-08-11 | 1995-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-09 | 1998-08-11 | 1999-02-10 | $7700.00 | Window Closed / Lapsed |