US4701663A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lamp having interference film
Assignee: Toshiba Corp
•
Filing: 1985-10-24
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Granted: 1987-10-20
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Expires: 2005-10-24
Abstract
Abstract A lamp includes a glass bulb sealing a filament therein. A light interference film is formed on a surface of the bulb. The film has at least five layers and is formed by alternately stacking a low-refractive index layer comprising silicon oxide and a high-refractive index layer having a refractive index higher than said low-refractive index layer. The low-refractive index layer contains, at least one additive selected from the group consisting of phosphorus and boron.
Inventors
- 👤 Akira Kawakatsu
- 👤 Yooji Yuge
- 👤 Noriyuki Hayama
- 👤 Tokuyoshi Saito
- 👤 Umio Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:06
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/28; H01K1/32
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
75 words
A lamp comprising: a glass bulb sealing a filament therein; and a light interference film formed on a surface of the bulb and having at least five layers, the film being formed by alternately stacking a low-refractive index layer comprising silicon oxide and a high-refractive index layer having a refractive index higher than said low-refractive index layer, said low-refractive index layer containing, at least one additive selected from the group consisting of phosphorus and boron.
Claim 2
Dependent Claim
75 words
A lamp comprising: a glass bulb sealing a filament therein; and a light interference film formed on a surface of the bulb and having at least five layers, the film being formed by alternately stacking a low-refractive index layer comprising silicon oxide and a high-refractive index layer having a refractive index higher than said low-refractive index layer, said low-refractive index layer containing, at least one additive selected from the group consisting of phosphorus and boron.
Claim 3
Dependent Claim
30 words
A lamp according to claim 1, wherein a total amount of phosphorus in terms of phosphorus and boron in terms of boron trioxide is about 3 to 20% by weight.
Claim 4
Dependent Claim
25 words
A lamp according to claim 1, wherein each of the low-refractive index layers contains the additive in an amount of 5 to 10% by weight.
Claim 5
Dependent Claim
16 words
A lamp according to claim 1, wherein the additive is in the form of phosphorus pentoxide.
Claim 6
Dependent Claim
16 words
A lamp according to claim 1, wherein the additive is in the form of boron trioxide.
Claim 7
Dependent Claim
22 words
A lamp according to claim 1, wherein the additive is in the form of a mixture of phosphorus pentoxide and boron trioxide.
Claim 8
Dependent Claim
31 words
A lamp according to claim 1, wherein each of the high-refractive index layers comprises at least one member selected from the group consisting of titanium oxide, tantalum oxide and zirconium oxide.
Claim 9
Dependent Claim
20 words
A lamp according to claim 1, wherein the light interference film is formed on the outer surface of said bulb.
References Cited (Backward Citations)
US2519722A
Cited
US3325666A
Cited
US4331901A
Cited
DE3227096A1
Cited
GB2128805A
Cited
US4588923A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |