US4814666A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron-beam existed display tube, the screen of which has a fluorescent component of a Eu containing red fluorescent component and a blue or green fluorescent component
Assignee: Mitsubishi Chemical Corp
•
Filing: 1986-07-15
•
Granted: 1989-03-21
•
Expires: 2006-07-15
Abstract
Abstract The present invention relates to an electron-beam excited display tube useful in such a display apparatus as a color cathode-ray tube. In accordance with the present invention, the content of europium as a activator for a rare earth oxysulfide fluorescent material used as the red emission component is within the range of 0.05 to 2.0 mol %, thereby providing a very bright and low cost electron-beam excited display tube without any uneven color reproduction, even when the display screen is seen from very close quarters.
Inventors
- 👤 Kazuhito Iwasaki
- 👤 Hideo Tono
- 👤 Susumu Omatoi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:31
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/187; C09K11/77; C09K11/7783; C09K11/7784; C09K11/7787; C09K11/7789; H01J29/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
An electron-beam excited display tube having a fluorescent layer formed from a fluorescent mixture, comprising: (i) a red emission component composed of a rare earth oxysulfide fluorescent material containing europium as the main activating component at a europium concentration of 0.05 to 2.0 mol %, wherein the rare earth metal of said oxysulfide is at least one element selected from the group consisting of yttrium, gadolinium, lanthanum and lutetium; and (ii) a green emission component whose chromaticity area (X/Y) of the CIE color specification system is defined by the points (0.19/0.76), (0.19/0.45), (0.24/0.41) and (0.39/0.60).
Claim 2
Dependent Claim
95 words
An electron-beam excited display tube having a fluorescent layer formed from a fluorescent mixture, comprising: (i) a red emission component composed of a rare earth oxysulfide fluorescent material containing europium as the main activating component at a europium concentration of 0.05 to 2.0 mol %, wherein the rare earth metal of said oxysulfide is at least one element selected from the group consisting of yttrium, gadolinium, lanthanum and lutetium; and (ii) a green emission component whose chromaticity area (X/Y) of the CIE color specification system is defined by the points (0.19/0.76), (0.19/0.45), (0.24/0.41) and (0.39/0.60).
Claim 3
Dependent Claim
21 words
The display tube of claim 1, wherein said europium concentration of said red component ranges from 0.05 to 1.5 mol %.
Claim 4
Dependent Claim
21 words
The display tube of claim 1, wherein said europium concentration of the red component ranges from 0.1 to 1.0 mol %.
Claim 5
Dependent Claim
134 words
An electron-beam excited display tube having a fluorescent layer formed from a fluorescent mixture, comprising: (i) a red emission component composed of a rare earth oxysulfide fluorescent material containing europium as the main activating component at a europium concentration of 0.05 to 2.0 mol %, wherein the rare earth metal of said oxysulfide is at least one element selected from the group consisting of yttrium, gadolinium, lanthanum and lutetium; (ii) a green emission component whose chromaticity area (X/Y) is defined by the points (0.19/0.76), (0.19/0.45), (0.24/0.41) and (0.39/0.60); and (iii) a blue emission component having a chromaticity area (X/Y) defined by the points (0.14/0.045), (0.14/0.19), (0.18/0.025) and (0.18/0.19) of the CIE color specification system, said fluorescent layer being defined by the chromaticity points (0.33/0.63), (0.61/0.36), (0.15/0.17) and (0.18/0.04) of the CIE color specification system.
Claim 6
Dependent Claim
134 words
An electron-beam excited display tube having a fluorescent layer formed from a fluorescent mixture, comprising: (i) a red emission component composed of a rare earth oxysulfide fluorescent material containing europium as the main activating component at a europium concentration of 0.05 to 2.0 mol %, wherein the rare earth metal of said oxysulfide is at least one element selected from the group consisting of yttrium, gadolinium, lanthanum and lutetium; (ii) a green emission component whose chromaticity area (X/Y) is defined by the points (0.19/0.76), (0.19/0.45), (0.24/0.41) and (0.39/0.60); and (iii) a blue emission component having a chromaticity area (X/Y) defined by the points (0.14/0.045), (0.14/0.19), (0.18/0.025) and (0.18/0.19) of the CIE color specification system, said fluorescent layer being defined by the chromaticity points (0.33/0.63), (0.61/0.36), (0.15/0.17) and (0.18/0.04) of the CIE color specification system.
Claim 7
Dependent Claim
21 words
The display tube of claim 4, wherein said europium concentration of said red component ranges from 0.05 to 1.5 mol %.
Claim 8
Dependent Claim
21 words
The display tube of claim 4, wherein said europium concentration of the red component ranges from 0.1 to 1.0 mol %.
Claim 9
Dependent Claim
24 words
The display tube of claim 4, wherein said fluorescent layer has a chromaticity area (X/Y) surrounded by the points (0.20/0.25), (0.21/0.20), (0.30/0.375) and (0.35/0.325).
Claim 10
Dependent Claim
89 words
The display tube of claim 1, wherein said green emission component is a fluorescent material selected from the group consisting of a zinc sulfide material of the formula ZnS:Cu/Al, ZnS:Cu/Au/Al or (Zn/Cd)S:Cu/Al, a Zn 2 SiO 4 :Mn fluorescent material, a ZnS:Ag/Cu fluorescent material, a Gd 2 O 2 S:Tb fluorescent material, an La 2 O 2 S:Tb fluorescent material, a Y 3 (Al/Ga) 5 O 12 :Ce fluorescent material, a Y 3 Al 5 O 12 :Tb fluorescent material and a Y 2 O 2 S:Tb fluorescent material.
Claim 11
Dependent Claim
45 words
The display tube of claim 4, wherein said blue emission component is a material selected from the group consisting of a zinc sulfide fluorescent material containing silver as the main activator, a Y 2 SiO 5 :Ce fluorescent material and a CaWO 4 fluorescent material.
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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |