Spectrally selective mirror and method for making same
First Claim
1. A spectrally selective, glare-reducing mirror for vehicles comprising:
- a substrate having front and rear surfaces; and
a multi-layer coating on said substrate including a thin layer of transparent, dielectric material and a very thin layer of metal, at least one of said metal and dielectric layers being applied directly to said substrate;
said metal layer having a thickness within the range of between about 25 and 150 angstroms to provide substantial transparency along with significant reflectivity;
said layer of dielectric material being positioned closer to a source of incident light to be reflected by said mirror than is said metal layer;
whereby said mirror provides desired luminous reflectance at a level which reduces reflected glare while providing appreciable spectral selectivity in the reflected light.
1 Assignment
0 Petitions
Accused Products
Abstract
A spectrally selective, glare-reducing mirror for vehicles which includes a substrate having a multi-layer coating on one side. The multi-layer coating includes a thin, transparent dielectric layer, preferably of titanium dioxide at a thickness of about 600-650 angstroms, and a very thin layer of metal, preferably of aluminum or silver, at a thickness of between about 25 and 150 angstroms. The dielectric layer is closest to a source of incident light to be reflected by the mirror. When applied to the rear surface of a transparent substrate such as glass, the metal layer may also be coated with light absorbing material such as paint for protection and reduction in unwanted reflections. In the preferred dielectric and metal thicknesses, a blue reflecting mirror results having a glare-reducing luminous reflectance between about 35% and 60%, while costs are reduced due to lesser required amounts of metal than in prior known mirrors.
459 Citations
53 Claims
-
1. A spectrally selective, glare-reducing mirror for vehicles comprising:
-
a substrate having front and rear surfaces; and a multi-layer coating on said substrate including a thin layer of transparent, dielectric material and a very thin layer of metal, at least one of said metal and dielectric layers being applied directly to said substrate; said metal layer having a thickness within the range of between about 25 and 150 angstroms to provide substantial transparency along with significant reflectivity; said layer of dielectric material being positioned closer to a source of incident light to be reflected by said mirror than is said metal layer; whereby said mirror provides desired luminous reflectance at a level which reduces reflected glare while providing appreciable spectral selectivity in the reflected light. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. A spectrally selective, glare reducing mirror for vehicles comprising:
-
a transparent substrate having a first/front surface and a second/rear surface; a thin layer of transparent, dielectric material on said second/rear substrate surface; a very thin layer of metal on said thin layer of dielectric material; and a protective coating of light absorbing material over said metal layer for absorbing light passing through said substrate, dielectric layer and metal layer and protecting said dielectric and metal layers against environmental effects; said metal layer having a thickness within the range of between about 25 and 150 angstroms to provide substantial transparency along with significant reflectivity;
said dielectric layer having an optical thickness of about one-quarter of the wavelength of light in the visible region of the spectrum;
said mirror having a luminous reflectance of between about 35% and 60% of light incident on said first/front surface of said substrate;whereby said mirror provides desired luminous reflectance at a level which reduces reflected glare while providing appreciable spectral selectivity in the reflected light. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
-
-
38. A method for manufacturing a spectrally selective, glare-reducing mirror for vehicles comprising the steps of:
-
1) providing a sheet of flat glass having front and rear surfaces; 2) coating one surface of said sheet with a thin layer of dielectric material of a desired thickness; 3) heating said coated glass to a temperature sufficient to allow bending of said coated glass; 4) bending said heated, coated glass to a desired curvature; and 5) coating said bent, coated glass over said layer of dielectric material with a very thin layer of metal having a thickness within the range of between about 25 and 150 angstroms. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
-
-
50. A method for manufacturing a spectrally selective, glare-reducing mirror for vehicles comprising the steps of:
-
1) providing a sheet of flat glass having front and rear surfaces; 2) coating one surface of said sheet with a thin layer of dielectric material of a desired thickness; 3) coating said coated glass over said layer of dielectric material with a very thin layer of metal having a thickness within the range of between about 25 and 150 angstroms to provide substantial transparency along with significant reflectivity; and 4) cutting said coated sheet into desired shapes useful as rearview mirrors for vehicles. - View Dependent Claims (51, 52, 53)
-
Specification