Patent US4288250A successfully refreshed from Google Patents.
US4288250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glass filter for contrast enhancement in CRT displays
Assignee: Hoya Corp
•
Filing: 1980-03-20
•
Granted: 1981-09-08
•
Expires: 2000-03-20
Abstract
Abstract A green contrast enhancement filter for CRT display devices which is prepared by adding about 0.1 to 1.5 part by weight of Cr 2 O 3 , about 0 to 0.5 part by weight of CuO and about 0 to 0.2 part by weight of NiO to 100 parts by weight of a base glass comprising about 4 to 70% by weight of SiO 2 , about 15 to 30% by weight of Nd 2 O 3 , about 0 to 25% by weight of one or more alkali metal oxides (R 2 O) and about 0 to 46% by weight of one or more divalent metal oxides (RO) such as MgO, CaO, SrO, BaO, ZnO and PbO, wherein the sum R 2 O+RO is about 10 to 50% by weight, about 0 to 25% by weight B 2 O 3 , about 10% by weight or less Al 2 O 3 and about 0 to 10% by weight each of TiO 2 , ZrO 2 , La 2 O 3 , Nb 2 O 5 and Ta 2 O 5 .
Inventors
- 👤 Toshiharu Yamashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:27
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/095; C03C3/062; C03C4/00; C03C4/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
210 words
A green filter glass having a sharp transmission peak in only the wavelength range of 540 to 550 mμ where the peak transmittance is to 10 to 16% through which 2 to 4% light having a wavelength of 610 to 620 mμ passes together with the light in the 540 to 550 mμ transmission peak consisting essentially of: about 0.1 to 1.5 part by weight Cr 2 O 3 , about 0 to 0.5 part by weight CuO, about 0 to 0.2 part by weight NiO and 100 parts by weight of a base glass composition consisting essentially of: about 4 to 70% by weight SiO 2 about 15 to 30% by weight Nd 2 O 3 about 0 to 25% by weight of an alkali metal oxide (R 2 O) and about 0 to 46% by weight of a divalent metal oxide (RO) such that the sum of R 2 O and RO is about 10 to 50% by weight about 0 to 25% by weight B 2 O 3 about 0 to 10% Al 2 O 3 and about 0 to 10% by weight of each of TiO 2 , ZrO 2 , La 2 O 3 , Nb 2 O 5 and Ta 2 O 5 .
Claim 2
Dependent Claim
210 words
A green filter glass having a sharp transmission peak in only the wavelength range of 540 to 550 mμ where the peak transmittance is to 10 to 16% through which 2 to 4% light having a wavelength of 610 to 620 mμ passes together with the light in the 540 to 550 mμ transmission peak consisting essentially of: about 0.1 to 1.5 part by weight Cr 2 O 3 , about 0 to 0.5 part by weight CuO, about 0 to 0.2 part by weight NiO and 100 parts by weight of a base glass composition consisting essentially of: about 4 to 70% by weight SiO 2 about 15 to 30% by weight Nd 2 O 3 about 0 to 25% by weight of an alkali metal oxide (R 2 O) and about 0 to 46% by weight of a divalent metal oxide (RO) such that the sum of R 2 O and RO is about 10 to 50% by weight about 0 to 25% by weight B 2 O 3 about 0 to 10% Al 2 O 3 and about 0 to 10% by weight of each of TiO 2 , ZrO 2 , La 2 O 3 , Nb 2 O 5 and Ta 2 O 5 .
Claim 3
Dependent Claim
20 words
The glass of claim 1, wherein R 2 O is K 2 O, Na 2 O or Li 2 O.
Claim 4
Dependent Claim
15 words
The glass of claim 1, wherein RO is MgO, CaO, SrO, BaO, ZnO and PbO.
Claim 5
Dependent Claim
11 words
The glass of claim 1, wherein RO is PbO or BaO.
Claim 6
Dependent Claim
9 words
The glass of claim 1, wherein RO is present.
Claim 7
Dependent Claim
41 words
The glass of claim 1, wherein the total amount of TiO 2 , ZrO 2 , La 2 O 3 , Nb 2 O 5 and Ta 2 O 5 is up to 20% by weight of the base glass composition.
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) | 1984-09-07 | 1985-03-09 | 1985-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-07 | 1989-03-09 | 1989-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-07 | 1993-03-09 | 1993-09-08 | $7700.00 | Window Closed / Lapsed |