US3944320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cold-light mirror
Assignee: EMI Group Ltd
•
Filing: 1974-07-26
•
Granted: 1976-03-16
•
Expires: 1994-07-26
Abstract
Abstract A cold-light mirror, especially suitable in the form of an ellipsoidal or hyberbolic mirror for an optical system for forming a light beam, comprises a metal substrate covered with a pigmented vitreous layer for absorption of infra-red radiation which is transmitted by an overlying dielectric interference layer.
Inventors
- 👤 William James McLintic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:27
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/281; G02B5/282; C; C03; C03C; C03C4/00; C03C4/08; C03C4/082; C23; C23D; C23D5/00; C23D5/02; G02B5/08; G02B5/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
A cold-light mirror comprising a metal substrate having a front surface and a rear surface, a first pigmented vitreous coating on the front surface of said substrate and a second pigmented vitreous coating on the rear surface thereof, each of said pigmented vitreous coatings comprising a black vitreous enamel capable of absorbing infra-red radiation and having a smooth glazed surface, and a dielectric interference coating on the surface of said first pigmented vitreous coating for reflecting visible light and for transmitting infra-red radiation.
Claim 2
Dependent Claim
83 words
A cold-light mirror comprising a metal substrate having a front surface and a rear surface, a first pigmented vitreous coating on the front surface of said substrate and a second pigmented vitreous coating on the rear surface thereof, each of said pigmented vitreous coatings comprising a black vitreous enamel capable of absorbing infra-red radiation and having a smooth glazed surface, and a dielectric interference coating on the surface of said first pigmented vitreous coating for reflecting visible light and for transmitting infra-red radiation.
Claim 3
Dependent Claim
28 words
A cold-light mirror as claimed in claim 1 in which said first pigmented vitreous coating includes a layer of pigment-free vitreous material forming the said smooth glazed surface.
Claim 4
Dependent Claim
120 words
An optical system for forming a light beam comprising a conic section mirror and a light source positioned on the axis of the mirror, the mirror being a cold light mirror having a metal substrate with a front surface and a rear surface, a first pigmented vitreous coating on the front surface of said substrate and a second pigmented vitreous coating on the rear surface thereof, each of said pigmented vitreous coatings comprising a black vitreous enamel capable of absorbing infra-red radiation and having a smooth, glazed surface, and a dielectric interference coating on the surface of said first vitreous coating, the dielectric interference coating being formed to reflect visible light from the light source but to transmit infra-red radiation.
Claim 5
Dependent Claim
120 words
An optical system for forming a light beam comprising a conic section mirror and a light source positioned on the axis of the mirror, the mirror being a cold light mirror having a metal substrate with a front surface and a rear surface, a first pigmented vitreous coating on the front surface of said substrate and a second pigmented vitreous coating on the rear surface thereof, each of said pigmented vitreous coatings comprising a black vitreous enamel capable of absorbing infra-red radiation and having a smooth, glazed surface, and a dielectric interference coating on the surface of said first vitreous coating, the dielectric interference coating being formed to reflect visible light from the light source but to transmit infra-red radiation.
Claim 6
Dependent Claim
27 words
An optical system as claimed in claim 3 comprising a housing enclosing the light source, the metal substrate of the mirror forming part of the said housing.
Claim 7
Dependent Claim
27 words
An optical system as claimed in claim 3 in which the pigmented vitreous coating includes a layer of pigment-free vitreous material forming the said smooth glazed surface.
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |