Patent US4804883A successfully refreshed from Google Patents.
US4804883A
Expired / Lapsed
US
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Front attachment for CRT. E.G. for a monitor or video tube
Assignee: Flabeg GmbH and Co KG
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Filing: 1987-09-01
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Granted: 1989-02-14
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Expires: 2007-09-01
Abstract
Abstract Front attachment unit for the cathode ray tube of monitors, television sets or the like, consisting of a sheet of glass, in particular a sheet of gray glass, anti-reflection equipment on the front side and an absorption coating on the rear side, whereby the absorption coating has metallic atoms. The absorption coating is single-layer and made of chromium, a chromium/nickel alloy or silicides. It is anti-statically adjusted and grounded. It is of a thickness which reduces the light transmission compared with a non-coated sheet of glass by approximately a third.
Inventors
- 👤 Dieter Muller
- 👤 Wilhelm Rein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:37
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/86; H01J29/89; H01J29/898; H01J2229/00; H01J2229/89; H01J2229/8913; H01J2229/8916
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
133 words
A front attachment for a cathode ray tube, comprising: a single inorganic glass sheet integrally having a rear side adapted to be applied ahead of the face of a cathode ray tube and turned toward the cathode ray tube, and a front side facing away from the cathode ray tube; an anti-reflection finish on said front side; an electrically conductive anti-static light absorbent coating on said rear side in the form of a single layer selected from the group which consists of chromium, a chromium/nickel alloy and a metal silicide of a thickness applied by magnetron cathodic vapor deposition which reduces the light transmissivity by approximately one quarter to four fifths of the transmissivity of a sheet of the glass not provided with said coating; and means for grounding said light absorbent coating.
Claim 2
Dependent Claim
133 words
A front attachment for a cathode ray tube, comprising: a single inorganic glass sheet integrally having a rear side adapted to be applied ahead of the face of a cathode ray tube and turned toward the cathode ray tube, and a front side facing away from the cathode ray tube; an anti-reflection finish on said front side; an electrically conductive anti-static light absorbent coating on said rear side in the form of a single layer selected from the group which consists of chromium, a chromium/nickel alloy and a metal silicide of a thickness applied by magnetron cathodic vapor deposition which reduces the light transmissivity by approximately one quarter to four fifths of the transmissivity of a sheet of the glass not provided with said coating; and means for grounding said light absorbent coating.
Claim 3
Dependent Claim
32 words
The front attachment defined in claim 1 wherein said light absorbent coating reduces the light transmissivity by approximately one third by comparison with a sheet of glass not provided with said coating.
Claim 4
Dependent Claim
22 words
The front attachment defined in claim 2 wherein said light absorbent coating has a surface resistance of substantially 0.5 to 20 kiloohms.
Claim 5
Dependent Claim
20 words
The front attachment defined in claim 3 wherein said light absorbent coating has a surface resistance of substantially 1 kiloohm.
Claim 6
Dependent Claim
17 words
The front attachment defined in claim 1 wherein the glass sheet is composed of clear float glass.
Claim 7
Dependent Claim
33 words
The front attachment defined in claim 5 wherein the light absorbent coating reduces the light transmissivity of the glass sheet composed of clear float glass to approximately 60% of its original light transmissivity.
Claim 8
Dependent Claim
17 words
The front attachment defined in claim 1 wherein the glass sheet is composed of gray float glass.
Claim 9
Dependent Claim
33 words
The front attachment defined in claim 7 wherein the light absorbent coating reduces the light transmissivity of the glass sheet composed of gray float glass to approximately 40% of its original light transmissivity.
Claim 10
Dependent Claim
15 words
The front attachment defined in claim 1 wherein said glass sheet is machine-made gray glass.
Claim 11
Dependent Claim
33 words
The front attachment defined in claim 9 wherein the light absorbent coating reduces the light transmissivity of the glass sheet composed of machine-made gray glass to approximately 21% of its original light transmissivity.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |