Cold-light mirror
AssigneeThorn Electrical Industries Limited
InventorWilliam James McLintic
Life of this patent
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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.
Claims5
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.
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.
Dependencies are inferred from the claim text.