Multilayer optical filter for producing colored reflected light and neutral transmission
First Claim
1. An optical filter, including:
- a substrate having a surface, and a coating supported by the surface of the substrate, said coating including a set of alternating layers formed of material having high refractive index and substantially quarter-wave optical thickness, and material having low refractive index and substantially quarter-wave optical thickness, where the thickness of each layer is selected so that the filter has a reflectance spectrum exhibiting a ripple over a first segment of the visible spectrum but exhibiting no significant ripple over a second segment of the visible spectrum, so that the reflected light having wavelength within the first segment is sufficient to give the filter a desired aesthetic color, and where the thickness of each layer is selected so that the filter reflects substantially all electromagnetic radiation having wavelengths in the near-infrared range.
4 Assignments
0 Petitions
Accused Products
Abstract
A short-wave-pass optical filter, that includes a partially absorbing or transparent substrate coated by a set of layers having specified quarter-wave optical thickness, and is designed to reflect visible radiation of a selected color while transmitting visible radiation and maintaining a neutral color balance. The coating includes layers having a high refractive index alternating with layers having a low refractive index. The refractive indices and layer thicknesses are selected so that the filter'"'"'s reflectance spectrum exhibits a ripple over a first segment of the visible spectrum but no significant ripple over a second segment of the visible. The filters may be used as sunglass lenses that have a selected color (such as blue, orange, or violet) when viewed by one other than the sunglass wearer, while permitting the wearer to perceive transmitted light with a correct color balance. The design of the inventive filter is preferably optimized to have the desired optical properties while being conveniently and repeatably manufacturable.
-
Citations
23 Claims
-
1. An optical filter, including:
a substrate having a surface, and a coating supported by the surface of the substrate, said coating including a set of alternating layers formed of material having high refractive index and substantially quarter-wave optical thickness, and material having low refractive index and substantially quarter-wave optical thickness, where the thickness of each layer is selected so that the filter has a reflectance spectrum exhibiting a ripple over a first segment of the visible spectrum but exhibiting no significant ripple over a second segment of the visible spectrum, so that the reflected light having wavelength within the first segment is sufficient to give the filter a desired aesthetic color, and where the thickness of each layer is selected so that the filter reflects substantially all electromagnetic radiation having wavelengths in the near-infrared range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
9. A sunglass lens, including:
-
(a) a substrate that is absorptive of ultraviolet electromagnetic radiation and is partially absorptive of visible radiation, said substrate having a surface and a first refractive index; and (b) a coating on the substrate'"'"'s surface including layers of material having a high refractive index and substantially quarter-wave optical thickness alternating with layers of material having low refractive index and substantially quarter-wave optical thickness, the thickness of each layer being selected so that the lens has a reflectance spectrum with a ripple over a first segment in the visible range but has no significant ripple in a second segment in the visible range, so that reflected light having wavelength within the first segment is sufficient to give the lens a desired aesthetic color, and the thickness of each layer being selected so that the lens reflects substantially all electromagnetic radiation having wavelengths in the near-infrared range. - View Dependent Claims (10, 11, 12, 13, 14, 15)
-
-
16. An optical filter, including:
-
(a) a substrate having a surface and a refractive index; and (b) a double quarter-wave stack coated on the substrate'"'"'s surface and capable of reflecting substantially all electromagnetic radiation in the near-infrared range, said stack including a number of alternating layers characterized by refractive index and a substantially quarter-wave optical thickness is selected as a result of an iterative optimizing process so that the filter'"'"'s reflectance spectrum has at least one rippled segment in the visible spectrum and at least one non-rippled segment in the visible range. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
-
Specification